When Severus promised Lily to bring her to a seawitch, Lily had thought that was an exaggeration. She hadn't been expecting...this.

The witch was woman on top, draped in pale pink-stained seaweed, and instead of one tail, she had eight bright pink tentacles. She was stirring some sort of pot that glowed a menacing fuchsia. Lily's red hair would definitely clash with the ambiance.

Severus pushed aside the gauzy curtain in front of the cave and prodded Lily forward. "Come on," he said. "It's rude to keep her waiting, don't you think?"

Still Lily hesitated, her green tail swishing side to side indecisively. "I'm not sure, Sev. I'm a little—"

"Frightened?" The seawitch had spotted them, and now approached with a wide grin that reminded Lily a bit of the sharks that frequented the same sunken ships that she did. "Now, now, dear. There's no need to be scared. Come in, tell me what it is I can do for you."

Lily and Severus swam through the curtain to join her.

"Tell her what you told me," Severus said, nudging her with his tail. "She can help, I promise."

"Well—okay," Lily said dubiously. "I'm a half-mer, er—Madam Seawitch—"

The seawitch's grin widened. "Dolores, dear."

"Dolores. I'm a half-mer, and during my time on land I've become completely enamored with human culture. I'm an aspiring anthropologist, you see. And, well, I was hoping—I was hoping you could help my legs last longer."

Dolores was still smiling. "Well, dear, I'm afraid I haven't met many half-breeds. Am I right in saying that when you emerge from the sea, you only have twenty-four hours before your legs turn back into a tail, correct? And then twenty-four hours until you can go back on land with legs. That's not very conducive for a thorough study."

"It's not," Lily agreed, bristling a little at her half-breed comment. "I was hoping to go undercover. See how humans act around other humans, take notes on their behavior—"

"I understand." The seawitch turned back to her cauldron. "Severus told me you might be coming, so I took the liberty of brewing a little something." She scooped the potion into a vial, then held it out to Lily. When Lily reached out to take it, however, Dolores snatched it back. "One teensy little caveat," she said sweetly. "I require something of you in return."

Lily began fishing around in her bag. "Of course. I have several gold coins recovered from an old human shipwreck—"

"Not your money, dearest. I need something of the humans'." Dolores held the vial up to the light. "The humans only have three sources of power, called the Deathly Hallows. The palace by the sea holds one of them." She set the vial of potion on the lip of the cauldron. "The Cloak of Invisibility. I want it."

"That's all?" Lily asked warily. "You want me to steal from the Royal Treasury?"

"I don't think it'll be quite so easily accomplished." The seawitch pulled a scroll from behind her, unfurling it as she spoke. "These are my terms. You will have your legs for a week, but if you goes back in the sea for any reason, if your legs so much as touch the ocean, they'll turn back into a tail permanently."

Lily read over the terms. Freshwater would not have any effect, so drinking while human would be permissible, but so much as a toe in saltwater would unravel the spell and leave her with a tail forever. No more midnight strolls on the beach, no more visits to her human friends. But avoiding the ocean for a week didn't seem too hard...

"One more thing," Dolores added as Lily reached for the proffered quill. "Should you fail, and not bring me back this cloak by the end of the week, I will steal your voice."

"My voice?" Lily asked, her tail flicking in surprise.

Dolores swept the quill through the water carelessly. "Just an insurance policy. I'm sure you understand."

Lily took the quill. "What do you need the Hallow for?" she asked.

Dolores was smiled indulgently. "I'm an avid collector of magical items," she said. "Now come along, dear. Light is wasting, and this counts as your first day."

Lily signed her name.

James was hiding.

This in and of itself was not unusual; he often hid from his duties, with "annoying regularity", according to his dear mother. What was odd about it was that no one was able to see him, even when they walked into the parlor where he sat with his book, remarked on the oddness of a roaring fire in an empty room, and then left.

It appeared that the cloak he and Sirius had nicked from the locked vault in the second dungeon was somewhat special after all. When they discovered that the hidden room they'd spent the better half of an hour trying to break into was empty, save for a dusty old cloak, Sirius had stormed out in disgust. James figured it would at least make a good blanket, and took it anyways. What he had not figured was that it would turn out to be the legendary Invisibility Cloak.

When Remus appeared in the doorway, James let the cloak slide to the floor.

"There you are," Remus said, relief coloring his voice. "The queen asked me to fetch you ages ago. No one's been able to find you. She needs you to interview some marine biologist looking to stay at the castle and use our resources."

James, who had been hoping for something more interesting from the man who had been tirelessly searching for him, stuck his nose back in his book. "Make Sirius do it."

"Sirius isn't actually a prince."

"Really? Has anyone told him that?" James waved a hand, not looking up and settling deeper into his armchair. "You do it, then. As my Official Royal Advisor, you are now qualified to do whatever duties I deem you fit for."

Remus groaned. "Sirius and I were going to dinner."

"Have the chef make you something and eat during the interview."

"James, you do know the topic of marine biology isn't exactly conducive to a romantic atmosphere."

"Isn't it? Perhaps that's why I've had miserable luck with women." James idly turned a page. "It's my day off, Remus. Call me if anything interesting happens."

Remus paused on his way slouching out the door. "Actually, there was. Apparently an ancient magical artifact went missing from the vaults. You wouldn't happen to know anything about that, would you?"

James shook his head, surreptitiously sliding the cloak under his armchair with his foot.

"I see. And the fact that you appeared from nowhere earlier, that wouldn't have anything to do with the magical artifact you're so desperately trying to hide from me?"

James leapt up, swearing. "Damn it, Moony, why are you so damn perceptive?"

"It's a curse," Remus said dully. "I won't tell anyone, if only because I suspect Sirius had more to do with the theft than you. But you have to interview the marine biologist. She's waiting in the foyer."

"Fine, fine. Have a nice dinner with Sirius." He spat the last part like it was a curse, and to his irritation Remus merely smiled.

"I will, thank you."

James left the cloak under the armchair (because who on earth would think to look there?) and slunk down to the foyer where a woman was indeed waiting for him. Her bright orange hair seemed damp and fell loose and curled about her shoulders. She wore a short-sleeved pale blue dress that hit at her ankles, revealing brown boots. James dragged his gaze up from her ankles to her face, which looked displeased at having been forced to wait.

"Apologies," he said smoothly, heading off a complaint. "I've been incredibly busy today. Would you care to follow me into the drawing room, where we can sit comfortably?" Not waiting for her to answer, he marched through the white double doors, expecting her to follow. She did, slipping slightly on the polished marble flooring. He sat with a flourish in the armchair closest to the large window, and she sat gingerly across from him. After nothing from the chair she sat in leapt to attack her, she settled into the seat.

"Thank you for seeing me," she said. Her voice was huskier than he expected, as if she'd been gargling salt water while he'd lurked upstairs reading. "I realize I'm putting you in an odd position."

"Well, we live in a coastal kingdom," James allowed. "The merpeople wouldn't fault us for wanting to study the ocean."

The woman leaned forward. "Your Highness, I've had...close contact with merpeople. I believe this puts me in the unique position to tell you that yes, they will fault you. They will see you as encroaching on their territory.,"

James ran a hand through his hair. "Then why are you here?"

"Because I believe the work I do is important." The woman was staring at him in a way that struck him as odd, her eyes wide and unblinking. "I want to improve relations between merpeople and humans. I recognize that that is a controversial wish—"

"Not to me," James interrupted. "Very well. I have a few questions for you, Miss...?"

"Lily," the woman said.

James paused, but she didn't continue. "Miss—er—"

The woman—Lily—paused for a moment. Then she seemed to remember that it was impolite to call a woman by her first name, and supplied him hastily with her last. "Evans. Lily Evans."

Her falter intrigued him. "Miss Evans. Where did you attend schooling? Forgive me, but we don't find many female scientists these days."

Miss Evans blinked, finally. "Hogwarts. I don't know if you're familiar—"

A wry smiled was twisting on James' lips. "I'm very familiar. I attended there myself. How old are you, Miss Evans?"

"N-nineteen," she said, her cool demeanor faltering.

"Ah, we would have been in the same year!" Smile widening, James continued. "I think I may have seen you around a few times. Slughorn sure was a handful, wasn't he?"

"Y-yes," Miss Evans stammered. "He was."

James propped his chin on his hand. She wasn't a skilled liar. He switched tactics. "What do you think of the colony of merpeople that live off the coast?"

She regained her composure surprisingly quickly. "I've studied their behavior as closely as one can from land, and I believe that, with a tactful approach, they would be open to negotiations for an alliance."

"Negotiations," he repeated. "With whom? Who speaks Mermish?"

"I do," she said. "I have a friend who is a merhuman."

James' eyes widened, forgetting briefly that she'd been lying to him and he'd been interrogating her. "Really? Who? Do they breathe underwater as a human, too? Can they control the change?"

Miss Evans looked shocked. "I—I did interview her as a part of my research. I plan on including my findings on half-mers in my thesis."

James tilted his head. "I don't know if I can trust you, Miss Evans."

He'd expected to unsettle her again. Instead, she surprised him by smiling. "And I don't know if I can trust you, your Highness. Isn't life funny that way?"

James laughed. "You're hired, Miss Evans. Stay here—I'll send a maid to bring you to your new room. I expect weekly progress reports."

Miss Evans nodded her gratitude, but there was something in her eyes that made him think she had no intention of staying indefinitely.

James wanted to call her bluff, to question her further. But something about her beauty was arresting; he couldn't bring himself to say anything that would cause her to leave. So he went to find his mother to arrange Miss Evans' stay.

Lily hadn't ended up needing the fake credentials Frank had prepared for her, and for that she was grateful. He and Alice were waiting for her in town, outside a small dress shop Lily planned on patronizing.

Alice ran to hug her. "How did it go?"

"Fine," Lily said. "I may need to introduce you to the prince as my half-mer contact, though. All my personal experience will need to be passed off as interviews with you. I wouldn't ask you to reveal yourself unless I have to—"

"Say no more," Alice said, holding her at arm's length so as to peer into her eyes. "I'd be happy to help you in your subterfuge. And Frank and I will treat you to your wardrobe for the week."

Lily tried to refuse, but Frank ushered her in. "We only ever need a few dresses for Alice, since she's only on land for a day at a time. We have the budget for some for you."

"And once your week is up, you can continue to wear them whenever you surface instead of just borrowing mine," Alice smiled sweetly. "Though that one does look lovely on you."

"What's your plan?" Frank asked. "About the Hallow, I mean."

"I don't really have one," Lily admitted as Alice waved a tailor over. "He seems surprisingly receptive to the idea of working with merpeople. I wonder...I wonder if I might be able to set up a meeting with Dumbledore."

Alice froze. "You really think Dumbledore would approve of your seeing the seawitch?"

"Well," Lily hedged, "I hadn't thought that part out yet."

The tailor bustled over. "I'll take you into the back room, dear," she said. "What are you looking for?"

Lily opened her mouth to answer, but Frank cut her off. "Three day dresses and a ball gown will suffice, don't you think?"

Alice was nodding. "In case of a special event, yes. And we'll need a few underthings as well—she's just moved from out of town and her wardrobe won't be delivered for another week, poor thing."

The seamstress nodded sympathetically, taking Lily's arm and making to drag her away.

"You can't," Lily protested. "It's too much—"

Frank waved a hand. "It's still my mother's money," he said. "She's spent it on worse causes than you."

As Lily was led into the back, she wondered what, exactly, she'd gotten herself into.

With every step Severus took, he hated land more. Dusk was falling, hopefully obscuring any of the human's view of him emerging from the sea. The castle loomed ahead, imposing but beautiful, and Severus' heart skipped a beat. Lily was in there, somewhere.

She was too good. She wouldn't have it in her to take anything from the filthy human prince. But he wouldn't let her lose her legs, her access to humanity. Severus might not have been able to understand her love of the humans, or how she felt anything but disgust at how her tail split, like his, but he knew they were important to her. He couldn't let her squander her life underwater for a week of life in a castle.

She didn't know what was best for her. He did.

Lily was given a room that overlooked the ocean, with seafoam green walls and pillows shaped like shells. Whoever had appointed her this room must have wrongfully assumed that she longed to be under the sea, swimming with merpeople and frolicking in the waves.

She drew the curtains to block out the view and sat down at the desk to draw out a plan.

Pens and paper on the surface were always so odd; the paper ripped easily, and the squid ink stayed in the jar when she opened it. Dipping the pen into the jar, she began to compose her plan.

She would need to spend time by the ocean, pretending to take notes on the water quality or whatever, but in reality watching the humans on the beach. How did they interact with the threat so close at hand? She often saw them, spread out in chairs with their children shrieking and playing, seemingly unaware of the danger. How did they do it?

At least being in the castle gave her an excuse to dine with human nobility. Perhaps she could understand why the humans put their faith and money in them. They didn't seem to be the wisest or bravest or kindest or shrewdest, as the leaders underwater had to be.

There was a knock at the door. Lily hastily placed the nearest book on top of her notes and rose to answer it.

The prince stood in the door. "My mother has requested your presence at dinner," he said. "I was running late myself, and figured I'd offer to escort you." He offered his arm.

"I don't think I'm dressed properly—"

Prince James waved this away. "Dinners with my mother tend to be casual affairs. It'll just be my brother and I, and a few members of my mother's court."

At least the dress was new. Lily looped her arm through his and allowed him to lead her to the dining hall.

It was not what she had expected. The hall was large, yes, but the many tables stood empty, save for a long one at the end of the room. A stately woman Lily recognized as the queen sat in a green velvet dress, laughing at something a handsome man with long, dark hair had told her. James led Lily to the table, depositing her next to a man in a frayed brown suit and then kissing his mother on the cheek.

"You must be Lily," the man said, his eyes smiling. "I'm Remus." He shook her hand rather than kissing it, and Lily hoped this meant that he regarded her as a colleague.

"The newest member of our little court," the queen announced with a hint of laughter in her voice. "We've never had a marine biologist visit. We've never had anyone other than James interested in the merpeople. And with the latest threats from underwater, we're happy to have any help."

Lily gave a deep curtsey, a maneuver she still found difficult to do with legs. Luckily, her full skirt hid how oddly her knees bent. "Your Majesty," she said. "Thank you for hosting me."

"Please," the queen said, laughing. "Call me Euphemia."

The man next to her leaned over Remus, his hand outstretched. "Sirius Black. Royal Pain." Lily took his hand, her lips twisting into an odd smile as she sat down.

"Finally," James said, raising his hands towards the skies. "He admits it!"

"Where's Peter?" the queen asked. "I thought you said he'd be joining us."

James shrugged. "Went for a walk, or something."

"Moody and Shacklebolt have been held up," Remus said. "I'm afraid it's just us for dinner, Euphemia."

"No matter," she said briskly. "Sirius, dear, would you run to the kitchens and let them know we're ready?"

Sirius pushed back from the table, his hand lingering for a moment on Remus' shoulder, then disappeared through a side door. Lily noticed the emptiness of the room, a distinct lack of all the servants she'd read about and seen on her brief previous jaunts through town.

James caught her looking around. "A lot of the servants left after the last threat from the merpeople," he explained. "And the rest we let go, except for the essential lot."

"What would you know about the last threat, Lily? In your...expert opinion." Euphemia asked airily enough, but something in her eyes was sharp.

Lily cleared her throat. "From my research and experience" (i.e.: her life up until this point) "it's actually a radical faction of human-hating merpeople. The vast majority appear content to coexist and live separately." She didn't mention those half-mers who were looked down upon by even that vast majority.

"Well," Euphemia said, as Sirius returned. "That's comforting, at least. My son tells me you speak Mermish?"

"I do."

"Good. We've found a document that washed ashore earlier today that we haven't been able to decode. Maybe you'll be able to take a look at it."

A man in a white chef's coat backed through the door, his arms laden with plates. James and Remus rose to help him carry them to the table. Sirius tucked his napkin into the collar of his shirt.

James set a platter of what looked like blackened sea bass in front of Lily, who stared into its deadened eyes in horror. She'd known humans ate fish but...knowing and seeing were two very different things. What was the word for humans who didn't eat fish.

"I'm actually..." she scrounged for the word. "Vegetable. I'm vegetable." No. That didn't sound right.

Sirius raised an eyebrow. "You're...a vegetarian?"

That was it. "Yes," she said. "That's what I said."

"You said vegetable."

"That's ridiculous."

"Enough, children," Euphemia said. "Lily, we have some steamed vegetables as well—Remus, dear, please pass them down—"

Lily accepted the bowl gratefully, relieved as the dead fish was moved away from her. "I'm sorry; I don't mean to be an imposition."

"Of course not." Euphemia tucked into dinner. "As soon as you're done, you'll dive right into translating the message we found and prove yourself useful."

Lily did not prove herself useful, but only because there was no way in hell she was translating this document.

It was a letter from her sister.

Dear Lily,

I heard about what you did. I haven't told our parents yet, but you'd better hope you fail and end up with a tail forever or you'll be eaten alive by those humans. I can't believe you'd go and flaunt those freakish things with the humans. I haven't told Vernon about you yet, and it's getting very hard to explain your absence.

Petunia

Lily didn't know how she'd heard, but the message in the bottle had apparently washed up right outside the castle, just as Petunia had undoubtedly intended. Lily set the paper aside in disgust. Trust Petunia to ruin her first ever assignment.

Instead of translating, Lily wrote a letter:

To the humans:

Those of us who walk among you regret that we cannot serve as ambassadors without facing discrimination from both sides of the conflict. War is not necessary, but you must show the first effort.

A friend

"From a half-mer?" James asked skeptically, holding up her "translation". "Are you sure? We haven't heard or seen from any of them."

"Well, they wouldn't exactly make their presence known," Lily said crossly. "Not when risk of discovery means imprisonment on land and shunning under the sea."

James raked a hand through his hair. "Imprisonment? There's no law—"

"It's not official imprisonment," she said sourly. "People kidnap half-mers, and when they turn back peel off their scales and sell them, one by one. I once had to break a friend out of captivity, but not before she'd lost two scales." She shuddered at the memory. She'd been close to turning back herself by the time she'd freed Alice, and the two had gotten a serious talking to from Dumbledore when they returned to school.

"That's awful," James said, setting the paper down. "I'll talk to my mother, see if we can't get some laws into effect banning that sort of thing." He tilted his head, taking in her tired appearance. "How would you like to go to lunch with me tomorrow?"

Lily blinked. "Lunch? Why?"

James smiled faintly. "I was...well, I was hoping we could talk more about mer-human relations. I've always wanted to open communication with their leader, what's-his-name—"

"Dumbledore," Lily supplied promptly. "He's absolutely wonderful."

"Have you heard much about him?"

Lily wanted to jump in and exclaim, Heard of him? I've met the man! He's tutored me! He's spectacular! But, for obvious reasons, could not. "My half-mer contact," she explained lamely. "She...talks a lot about him."

"So," James said, now looking nervous. "Lunch? Tomorrow? With me? There's a great little restaurant I've heard about—no seafood, of course," he said, grinning. Lily's heart warmed.

"Of course," she said. "I'd love to."

Day 2

Severus was lurking in the shadows of an alleyway, waiting for an opportunity to sneak into the castle, when he saw them.

The flash of red hair, the swirl of emerald skirts so close to the color of her tail. Lily was dismounting from a carriage, her feet slipping to find purchase on the cobblestones. Gracefully, the human prince descended beside her, laughing. Laughing at her.

Severus' fists clenched, but Lily was laughing too. He edged closer.

"I've never had tea in a tearoom before," she was admitting. She looked lively, surrounded by a small lush garden in front of the shop, her dress trailing across the spring grasses. On land, her hair hung below her elbows, rather than floating up around her ears. Severus had seen her out of the water before, but not in a while. While Lily loved exploring, he would always wait in the shallows for her to return, splashing in just in time for her legs to turn back into a tail.

The prince was gasping dramatically, ushering her inside. Severus could see them through the window. Lily touched his arm, brushing her hair behind her shoulder as she laughed.

He needed to get inside that castle, soon.

Lily was so caught up in a story James was telling her she almost forgot to be taking notes on the human behavior around her. Though, truth be told, it was not much different than a mermish cafe.

"You know what's always fascinated me?" James asked idly, stirring far too much sugar into his tea. "Merpeople's magic. They've got so much of it."

"Not everyone has magic," Lily said quickly. "Only a few seawitches and the like. Even then, their powers are unstable and unpredictable."

James tapped the small silver spoon against the edge of his teacup. "All we have is the Invisibility Cloak, which isn't even particularly impressive magic—" he broke off. "I wasn't supposed to tell you that."

Lily's heart skipped a beat. He knew about the Hallow. "Your secret is safe with me," she assured him. "But I've always been so interested in the Hallows...could you tell me anything about it?"

It had been a mistake. He was closing off. "What were you going to do today?" he asked. "Did you have a plan to study the merpeople?"

"Oh—er, yes," she said quickly. "I was planning on meeting up with my half-mer contact again today. She said she might be able to, uh, fetch me some artifacts now that I have somewhere to keep them and study them." Lily watched him, to see if he grew suspicious. But he was just nodding, as if this sounded entirely reasonable.

"When I was little, I used to wish I was a merman," he said. "Or a half-mer. I'd go swimming in the ocean and just pray and pray that my legs would turn into a tail."

Lily's blood turned cold. She had a feeling she knew exactly where this story was going, and she didn't like it at all.

"One day," he said, staring into his teacup, "When I was about eleven, I swam too far out. Sirius got scared and ran back home, but it was too late. I slipped under the water and couldn't breathe. And then I saw her."

He had been almost unconscious when she'd found him. His black hair floating around his face, his mouth open and trailing tiny bubbles. Despite her legs, Lily had always been strictly forbidden from going ashore until she was sixteen. But here was a stubbornly human boy, drowning in front of her.

"She had hair like yours," he remarked.

Exactly like hers, actually.

"And she swam me back to the surface and set me down on the beach. She had to have been about my age, and she saved my life." He took a deep breath, turning the teacup in his hands. The whole shop seemed to have faded away as Lily remembered leaving him on the beach, the sand darkening around his wet form, her tail tingling and splitting until she was the proud owner of two legs, wrapped in a scaly skirt that was quickly falling apart. "Ever since that day I've been determined to find make things right between humans and merpeople. To repay her."

Lily wanted to tell him. She wanted to grab his hands and tell him that that day had changed her life, too. She'd stood on dry land for the first time and taken in the view, and decided she wanted to know everything there was to know about the human world.

But instead, she took a sip of tea. "That's admirable," she said finally. "I hope I can help you."

"I think you already have."

Day 3

Lily spent a lot of time in the library, something James found quite odd. He'd assumed she'd come to his castle specifically due to its proximity to the sea, and figured she'd want to spend all her time down at the shore. Every time he'd offered however, she'd blush and refuse. Apparently she didn't want to go anywhere near the ocean, and was fascinated by the vast library.

Every time he stuck his head in, she was reading a different book, none of them on marine biology. She had a pile of history books, a few novels, and, curiously enough, a sociology textbook.

"Part of the reason I came here was for your library," she finally admitted. "It'd seem a shame to waste the opportunity."

He didn't entirely believe her. She'd gone completely white the day before while he'd told her about his experience with the mermaid, and he didn't know what to make of that.

Peter was waiting for him outside. "Remus told me about the Cloak," he said eagerly. "Can we take it out for a spin?"

"It's not a new carriage," James said. "It's all I have left of my father."

Peter left soon after.

James kept the Cloak on him at all times, ever since Lily had let slip her interest in it. He still didn't trust her entirely, but more importantly, he didn't trust himself around her. He'd had no intention of telling her all that yesterday, but it had all come out anyway.

He turned to reenter the library only to find her standing behind him, her wide eyes full of sympathy. "The Cloak," she said. "It was your father's? I'm sorry I asked about it yesterday, I—I didn't know it had sentimental value."

For once, she seemed to sincere James consciously decided to share with her. "He'd hidden it away, but after he died I took it upon myself to hunt for it. I only just found it."

She seemed sad, suddenly. "I see. If you don't mind my asking...what happened to your father?"

"Scalepox," he blurted out. "Sometimes the merpeople poison the fish they know is going to be eaten by humans. Usually, we can detect it, but..." he shrugged. "It was a year ago."

"I'm sorry." She took his hand. "I'm really, truly sorry. For what it's worth, poisoning fish is illegal underwater. So whoever killed your father is likely imprisoned."

James exhaled and changed the subject. "How about a walk on the beach? You look like you could use a break."

She started. "I—can't. Sorry. I've got a lot of work to do, and I was hoping to observe the town for a bit."

"Observe the town? Why would you need to observe the town?"

Her face turned bright red, clashing with her hair. "I—" he could practically see her thoughts racing. "I was hoping to see if I could spot a half-mer among humans. See how well they can pass, you know." She drew herself up, an attempt to regain composure. "My half-mer contacts can only get me so far."

"I see." James ran a hand through his hair. "Well, if you change your mind, you know where to find me."

He left her there in the hallway, gazing after him.

Euphemia delivered her another message that afternoon.

Dear Lily,

Dumbledore knows you've gone. He's not doing anything about it, and I don't know why. Severus is also missing, but I don't know where he's gone. The last time I saw him he was with you. I know he can't have followed you, but have you happened to have seen him? Dumbledore is starting to worry.

Petunia

Lily again drafted another letter of sympathy as a translation and handed it back to Euphemia, but she puzzled over the second note from her sister. Severus was missing as well? Very few people knew that Sev was a half-mer like her, but he hated the land. There was practically no chance he'd followed her onto land, and even if he had, he'd have to return to the sea every twenty-four hours.

The fact that Dumbledore knew was worrying. If he changed his mind and did something, would the seawitch's spell end? Would her legs turn back into a tail? She didn't want to think about it.

Staying away from the ocean was proving difficult. So far avoiding seawater hadn't been too hard, but eventually James would get too suspicious of her. The books from the library had been so perfect, though. Reading them had made up weeks and weeks of first-hand research. She only wished that, at the end of the week, she could bring them back with her.

And that was another thing. She knew where the Cloak was now—obviously, James had it. But she also knew that she could never steal it from him. The Hallow going missing would jeopardize his kingship and the faith of his people, and it was the last vestige of his father's memory.

She had a week. And then her voice would be lost forever, and she'd be back to a regular half-mer.

Might as well make the best of her last few days as a human.

Day 4

The next morning James noticed that something had changed with Lily. She sought him out almost immediately and requested a carriage ride.

"Do you have a particular destination in mind?"

She thought for a moment. "I want to have a picnic," she said finally. "I've read about them, and they seem lovely."

James agreed immediately, and went down to the kitchens to arrange it. When they met the carriage outside, Lily insisted that he teach her to drive.

"I'd like to learn to ride a horse, too," she said. "But I suspect this will be easier."

He sat beside her, wondering at how she'd never ridden a horse, and handed her the reigns. She was a quick study, but the ride was bumpy and jerky, and James feared for his life at several points. But watching her made it all worth it. Her long hair streamed out behind her, catching the dappled sunlight through the trees. She was grinning, leaning forward eagerly and talking to the horses, encouraging them forward.

When they reached the meadow, Lily patted the horses' manes and offered them each an apple, cooing over them.

"Have you ever met a horse before?" James found himself asking.

"No," she said wistfully, tucking her legs under her knees and sitting beside him on the blanket he'd spread out. "Where I'm from, we don't really have many horses. And the kind we do have you wouldn't recognize as horses."

That was odd, but he didn't want to push it. Not when she was in such a good mood.

After they ate, they lay side by side on the blanket, cloud gazing. Lily couldn't seem to get enough of the sky.

"It's so clear," she said, amazement seeping into her voice. "I just...the outline of the clouds are so sharp and visible. And the blue! I'll never get over it."

"Say something in Mermish," James said suddenly.

She turned her head to look at him and found that some of her hair was trapped beneath his shoulder. "Why?"

"I've never heard anyone speak it," he said. "I've heard that underwater it sounds like singing."

"It does," she said, her voice faraway. "It's like the most beautiful sound you've ever heard. Above ground, though..." her voice changed to a horrendous shrieking noise. She wrinkled her noise. "Not so much."

James became very aware of her body next to his, of the two inches between their hands. He'd only known her for a few days, but something about her made him feel so close. He reached for her hand, clasping her fingers in his. Her eyes met his for a split second, then she squeezed his hand, closed her eyes, and rested her head against his shoulder.

Day 5

Lily taught James Mermish, relishing in the sound of her own voice, even in the screeching of Mermish abovewater. She tried to memorize the cadence of her voice, to come to terms with the fact that she'd be losing her main method of communication in two days.

A strangled sob escaped her, but she passed it off as a cough. Two days.

She taught James with vigor, hoping that when she couldn't serve as an ambassador any longer, he would take up the mantle. Maybe, before she left, she'd tell him what she was. Maybe.

"We should go down to the ocean," James suggested once again. "Go for a swim, and speak Mermish underwater."

"Anyone can understand Mermish underwater," Lily argued. "It's abovewater that you have to determine the different sounds, and the written language."

For the better part of a day, they worked together. When James worked on grammar exercises, Lily read anthropology books. Maybe when she surfaced, after this was all over, she'd still have access to the library for the brief windows of time when she would have her legs. If she could ever show her face here again once her deception was revealed.

"Are you scared of swimming?"

James asked her out of the blue, and Lily realized she'd been given an easy answer to why she avoided the ocean. But for some reason, she couldn't take it and lie to him even more. No, not for some reason. She knew exactly why she didn't want to lie to him, even if she wasn't ready to admit it to herself.

"No," she said truthfully. "I love swimming. I just...not this week. Not now."

James didn't seem to want to let it go, but he went back to his work without pressing the issue, for which Lily was grateful. She nudged his foot with hers under the table, to show there was no hard feelings.

After another hour of silence, James said, "Tell me about swimming."

Her heart warmed at an excuse to ramble, to talk for ages. Swimming was easy to talk about, and she spoke until her throat went hoarse. And then, reveling in the pain of an overworked voice, she kept talking.

Day 6

Severus watched them go to the market on Saturday, following them through the crowd at enough of a distance that Lily wouldn't spot him. Not that she would be looking for him; she knew how much he hated being on land. Sickeningly, most of the stalls were selling fish and prawns and oysters, pearl jewelry and saltwater taffies.

Ahead, Lily was admiring a spiraling pink seashell on a string, and the human prince tied it around her neck. He paid for it, and then the two continued on—hand in hand, Severus noted with a sickening lurch to his stomach.

She wasn't going to do it. She was going to let the week expire tomorrow, and the seawitch would take her voice. He would have to do something, and he would need to get the prince out of the way first.

Day 7

Lily awoke late. She and James had been up in the library most of the night, talking about nothing and everything. Growing close to him had been a risk, but it had made everything worth it. Leaving him...she didn't want to think about it.

She crept down the stairs to the grand foyer, and was almost out the door when a voice behind her called out.

"Leaving so soon?"

It was Sirius, the man claiming to be James' brother.

"I was never staying long," Lily said.

"Then why did you make James fall for you?"

Lily winced. "I didn't...not on purpose. Believe me, I don't want to go."

Sirius gestured to a low bench. "Sit with me for a minute, then, before you leave."

Lily did so warily. She hadn't spoken with Sirius much during her time at the castle, and the words they had exchanged had mostly been jokes over the dinner table while Euphemia held court.

"I'm not really James' brother," Sirius said. "My parents are from the Noble and Most Ancient House of Black, and they advocated mainly for all-out war with the merpeople. It was horrible, living there. And after my mother found out I'd been seeing Remus...well, she told me not to come home again. James took me in when we were about twelve, and Euphemia is more of a mother to me than that awful woman in that old house ever was."

"Why are you telling me this?" Lily asked, her fingers tightening on the bench. She needed to get back before sundown, and while she still had several hours until then, she didn't want to take any chances.

"If you're running from something," Sirius said. "If you're not safe. This place is safe."

Lily almost found herself in tears. "I wish it were as simple as that," she said. "I really do. Thank you, Sirius, but I need to be gone by sundown."

Sirius stood, offering her his hand. "Then spend one last day with us. James and I were going to go riding; come with us."

Lily took the hand. "Alright," she said. "But don't tell James I'm leaving, please. I still need to decide how I'm going to break the news to him."

She had no idea how she was going to do it. But one thing was for certain: he deserved an explanation. Now to figure out how much to tell him.

James had been about to head down to meet Sirius when a folded piece of paper slid under his door.

The handwriting was unfamiliar, but it was addressed to him.

James,

Meet me by the pier at noon. I'll explain everything then, I promise. I'm sorry I've been lying to you for so long.

Lily

Sirius would understand if James never showed up, but he sent Peter to find him anyways and explain where he'd gone.

"Tell him to go without me," he said. "Or better yet, take Remus and you three go together. Maybe we'll meet up with you." Depending on what Lily had been lying to him about.

Sirius and Lily had saddled up the horses when Peter and Remus entered the stables.

"That's weird," Peter said. "Shouldn't you be down by the pier?"

Lily's heart skipped a beat. "What do you mean?" She asked quickly. "Where's James?"

"Said he was going to meet you by the pier, said something about a letter. Maybe there's been a mixup, we can swing by and get him."

Lily was already climbing on the horse. "I never sent any letter," she said. "Something's happening. I wouldn't have sent him to the pier." She nudged the horse out of the stables, working up to a gallop and then an all-out run.

For someone who'd never ridden a horse before, she had to say she was doing a fine job. Then again, she had no standards by which to judge her performance. Was she supposed to bounce this much? Her thighs were killing her.

But whoever wanted James down by the pier was more dangerous than bruised thighs.

Severus watched as the human prince approached down the empty pier, the crumpled letter in his hand. He stood up, and the prince saw him.

"Have you seen a redheaded girl?" he asked. "I'm supposed to be meeting her here."

"No you're not," Severus said. "I wrote that letter. Lily's not coming."

The prince frowned. "Who are you? How do you know Lily?"

"I'm an old friend," Severus said. "And I know her better than you. I know what she hasn't been able to do, what she's about to sacrifice for you." He advanced on the prince. "Where do you keep your Hallow?"

The prince went from confused to angry in a millisecond. "So that's what you're after. Was she sent here to get the Hallow from me?"

"Yes," Severus admitted. "But she won't do it. She's too weak." Severus raised a fist and struck the prince off the pier, knocking him unconscious as he fell. "But I'm not."

Lily reached the pier in time to see Severus slinking off towards the castle. He didn't see her, and she didn't have time to follow him. Just off the pier was a figure with messy black hair, floating facedown in the water.

Lily didn't think. She raced down the pier, her feet taking her nearly as fast as her tail could have. When she reached the end, she dove into the water—a perfect dive, leaving barely the hint of a splash. She could feel her legs gluing together, merging into a tail. Distantly, she realized that the spell hadn't broken yet. She was doomed to a tail forever.

She looped her arms around James' torso and tossed him back up onto the pier, praying she wasn't too late. He didn't appear to be breathing. Down the beach, she saw three horses skid to a halt, their riders disembarking. Remus, Sirius, and Peter. They began to sprint towards her.

It was too late. The sun may not have set yet, but she was already doomed. She could feel it in her throat, like something was bubbling up and threatening to spill out her mouth. Up on the pier, James began to cough up water. "Lily?" he croaked. When he saw her tail, his eyes widened. "I knew it! It was you all along—you're the mermaid girl who rescued me!"

All she could do was nod.

Her eyes found Sirius', who had doubled over to catch his breath at the end of the pier. She opened her mouth, and found she could still speak, albeit faintly. "Keep him safe," she said, her voice coming as if from a distance. "Don't give up the Hallow."

With a flick of her tail, she had vanished into the depths of the sea.

Alice found her in her old cave, the one she'd filled to the brim with as many human treasures as she could get her hands on. Splinters from the masts of great ships, chests full of gold and rubies, entire sets of silverware. She even had two books, though all that remained was the leather binding and wisps of what had once been paper. These remnants were all that she had left to hold onto from the human world.

Lily was sifting the gold through her fingers. Maybe she should give it to Alice and Frank; it's not like she would have much use for it anymore. The most she would see of the humans would be their skeletal remains at the bottom of the sea, and when she could stand to hold her head abovewater for more than a few seconds untransformed.

Alice swam in, her eyes full of pity and wonder. The only person who'd ever seen Lily's cave before had been Petunia, but Petunia never came in here unless she had to. Lily didn't meet Alice's gaze, only swam over to where she'd stashed her parchment and ink.

"Dumbledore wants to see you," Alice said softly. "He didn't say why."

I don't want to see him, Lily wrote. I want to be alone.

"Dolores is upset," Alice said, ignoring Lily's request. "She's going to send someone else."

Severus is already up there. He tried to kill James.

"Frank's looking for him. I saw him sneaking away from the beach yesterday. He said he'd explain all he could to the prince." Alice held out a hand. "Come with me to see Dumbledore. Maybe he can help."

Lily set down the quill, just shaking her head. Alice tugged at her, and she let herself be dragged through the water, offering only the occasional flick of her tail to help propel them forwards.

Dumbledore was waiting in his office at their old school, where he always seemed to be. Alice shoved Lily forward as soon as she'd knocked, then shut the door behind her, leaving Lily and the old merman alone. Dumbledore swam out from behind his desk, looking at her in concern.

"My dear girl," he began. "What you've undertaken for the sake of intellectualism is commendable."

Lily could only nod.

"I can undo the curse the witch put on your tail," he said, and Lily's head jerked up, barely daring herself to hope. "The curse she put was flimsy, and easily broken." He waved a hand over her tail, and though she didn't feel any different, the scales seemed to shine brighter. She hadn't even noticed they'd dulled. "As to your voice...I'm afraid I can't restore that without the aid of the Hallow."

Lily opened her mouth, but nothing came out. Of course.

"The human magic is part of what bound this curse to you," he said gently. "I won't need it permanently, but I will need to study it. I trust you know where to find this Hallow?"

She nodded slowly.

"The only other way to break the curse on your voice would be to kill the seawitch."

Lily recoiled.

"Those are the options," Dumbledore said sympathetically. "I can meet you by the human pier tonight. If you have the Hallow, I can reverse the curse. If not...we will look into other options."

Lily nodded. What else could she do?

When she pulled herself up onto the pier, she was so shocked to find James' hazel eyes staring into her own that she nearly fell back into the water. He offered her a hand to pull her up, and, dumbfounded, she accepted. They watched together as her scales receded, revealing first toes then calves then thighs, swirling to form a short green scaly skirt. She stood quickly, feeling underneath the pier for the proper skirt she usually kept stuck there for just this situation, hastily turning her back and pulling it up to her waist, where it met the fitted shirt she wore while swimming.

James took her hand. "I hoped you would come back," he said.

I almost didn't, she wanted to say. Instead, she just shook her head, smiling slightly. She gestured to her throat.

His grin faltered. "What's wrong?"

She opened her mouth and closed it, then mimed writing.

"Did you...lose your voice? I have tea back at the castle. Mum would love to chat over tea. About the whole mermaid thing."

Yes. About the whole mermaid thing. Well, tea would do until she could get her hands on a pen and paper.

Sat around the dinner table, helping herself to a cup of tea, Lily mimed writing again. Remus helpfully handed her a notepad, pen, and ink, in which she eagerly began scrawling truth, about why she'd come and why she'd left. Once she was done, the paper passed its way around the table. When it finally reached James, his jaws clenched.

"I—I can't give up the cloak. It's my last memory of my father." He looked to Euphemia. "And as important to this kingdom as the crown."

Lily reached for the paper again, her mouth moving silently.

"Would an interpretive dance help?" Sirius offered. "I'm quite good at charades, I'll have you know." Remus elbowed him. Peter slid the paper over to her.

It would only be for a few minutes, she promised. Think about it. This would be the first meeting between a Mermish leader and a human in...well, forever, I think. Think of it as a show of good faith. I won't let him go anywhere with it.

"Okay," James said, staring at the paper with Lily's words on it. "On one condition."

She raised an eyebrow.

"You stay on as ambassador." He slid the paper towards her, ready to receive her protestations, but she didn't move to take it. He forged ahead. "You said you have to change back every twenty-four hours; that's not a problem. We could build a pool for you, or better yet, a canal and reception room. To improve relations with the merpeople, making the castle more accessible to them." He was pacing now, his mind whirling. Despite her hesitations, Lily was impressed. She picked up the pen and wrote one word: Yes.

Epilogue

James joined Lily in the pool that evening, as soon as her hours with legs were up. He brought her a fresh change of clothing for the next day, placed in the cabinet with her name carved into it. Beside it were several others, one open and spilling clothes onto the marble flooring. That was Alice's.

Lily surfaced beside him. "Hello," she said, kissing him softly on the mouth. She ducked back under for breath before coming back up. "Come to practice your Mermish?"

"Underwater?" his eyebrows rose dramatically. "Lily! Anyone can understand Mermish underwater."

She ducked back down. "Yes, but I do like to breathe every so often." Her voice rippled through the water, faint to his ears above the water. She surfaced again. "For the next twenty-four hours, until I can change back into human, this is what it will be like. Only talking for as long as I can hold my breath." She sunk back until only her eyes were above the water level.

He brushed a floating strand of her hair away from her face tenderly. "We've been dealing with this for months," he said. "We can deal with it longer. Remus and Peter are working on ways to allow humans to breathe underwater for a short period of time. Something involving tubing, I don't really care about the logistics of it. But that will ease some things, won't they?"

She nodded, leaving her nose and mouth under the water. Her tail flicked forward, nudging his legs as they kicked gently to stay afloat. "You made history," she said, her voice muffled by the water. "I'm...proud of you."

"I did nothing," he said. "It was all you, Miss Evans. My marine biologist."

Lily splashed him, her eyes narrowing but her mouth twisting into a smile.

"Actually, there was something I wanted to ask you along those terms," he said. "Everyone's talking about how I'm the first prince to talk to the merpeople, but...there are still so many problems. The treatment of half-merpeople especially.

"I've been thinking about that," she responded. "My role as ambassador is helping." She moved closer to him until their chests were pressed together. "My role as your something is also helping."

"My something." James tucked a strand of hair behind her ear. "What about the first half-mer princess?"

Lily froze, only staying aloft due to the involuntary swishing of her tail. "The what?"

"Marry me," he said softly, his voice barely above a whisper. "Please, Lily Evans. Make history with me."

Smiling, Lily surged upwards, wrapping her arms around his neck and kissing him enthusiastically. "James Potter, of course I will."

A/N

This was...kind of a rush job. Though somehow twice as long as anything I've ever written (excepting, of course, my multi-chapters). Speaking of those, I'm really upset I haven't been able to recover my Royal Blues notes yet. Give me two weeks. I'll have them when I'm home.

I hope you enjoy this, even if it's not my best work. Be sure to check out the other writings from April's Jily Challenge, I know I can't wait to read the other entries! Now I'm off to watch the new John Mulaney special on Netflix and get some much-needed sleep in anticipation of finals.

Much love!

Alys