Rose Granger Weasley took a deep breath, keeping herself afloat on her back in the pond on her grandparents' land as the sun began to set. Summer was over, all of her paid leave from the National Magi-Marine Institute was used up, and after weeks of hiding in the country, she would be returning to London in the morning.

Days ago, Preston had owled to say that, finally, all of his things were moved out of their flat. It was now her flat alone, and it was time to sweep the floor and build a life without him. As break-ups go, it could have been worse. And it can never be easy. At least dear, dull Preston, an arithmancer in charge of monitoring the population density of the country's freshwater Lobalugs, had never proposed.

She was sinking and took another deep breath, her eyes on the clouds as they began to turn golden at their edges. The return to London and the institute and her flat was for tomorrow. She still had this last evening in the pond, and a strange sense of expectancy, like something was going to happen, like an electrical storm coming on. She felt it in the tips of her toes and fingers, at the roots of her hair.

Whatever it was, it would have to wait until her swim was over. Until then she took her precious, quiet, private time in what had been her favourite place in the world when she was growing up, spending summer days and nights here with her cousins, and with Teddy, and with his cousin…

Scorpius.

She bobbed to her feet when she heard the crush of footsteps on the gravel strewn over the dirt path to the dock. There he was, pacing toward the pond. No one else she knew walked like Scorpius, or reflected light in quite the same way, as if he was made of crystal. He'd been shorter than her until they were thirteen, the lingering effects of a sickly infancy. Then all at once he was made of long, sharp angles, quick movements, lost in his school robes. As an adult, he had settled into his own elegance, coming toward her now tall and pale and dressed in black at the end of a fine day.

The calm of the pond rippled and waved as Rose raised her arms and called his name.

"Your Nan said I'd find you here." He scuffed to the end of the dock on the smooth leather soles of his shiny black shoes.

"The dashing young research professor Malfoy has come all this way looking for me?" Rose said, blinking water drops out of her eyelashes.

He unbuttoned his suit coat and squatted at the end of the dock, getting closer to her level. "Yeah, something's come up at work. And I find myself agreeing with your Uncle Percy that there's no one better for me to discuss it with than you."

Rose didn't get out of the water but she did sling one elbow over the edge of the dock wetting the wood and splashing his shoes.

"Two things, Scor," she began. "Number one: what in the world could I possibly have to offer you and Percy in terms of the magical fertility research clinic? And number two: why in the world would anyone come to a summertime swimming hole dressed in a double-breasted, banker-stripe, charcoal wool suit?"

He laughed through a scoff. "The temperature's been getting down below ten degrees at night, perfectly appropriate weather for a lightweight wool weave. My wardrobe isn't ruled by the calendar, but by common sense. Unlike SOME people," he said, flicking away a droplet of water hanging from the end of her fine, slightly long Weasley nose. "Yes, you're a very impressive magizoologist, but you're still warm-blooded yourself. Aren't you freezing in there?"

She smeared the toe of his shoe with her wet hand. "A strong girl like me? No, I am thriving in it. But I can see how I might not risk it if I was as delicate as SOME people."

He clucked his tongue. "Rose, you know that's no way to tease me, questioning my hardiness. Twenty-five years we've been friends and I have never once claimed to be as vigorous as you."

She faked a pout, though she was actually pleased to hear him speak like this. Especially since it was the truth. She pushed off the dock, calling up to him as she went floating off on her back again. "I'm not trying to shame you, Scor. I'd just like it if you came in here to talk to me."

Scorpius blinked and called back. "Into the water?"

"Where else? Who knows when we'll have the chance again," she said, swimming upright now, treading water. "And if you have to bore me with dear Uncle Percy's research, which I am assuming doesn't have a single sea creature in it, then you can at least do so without ruining my last night in the pond, this holy refuge of my childhood."

Without a word, Scorpius stood up.

Rose darted back to the dock. "Are you leaving already?"

What he was doing was smirking as he slid his jacket off his shoulders, folded it carefully, and laid it on the weathered grey wood. He glanced at Rose before fixing his attention to unfastening his cufflinks.

She shouted a laugh. "You're just going to strip off there, while I watch?"

"So stop watching," he said, untucking his shirt from his trousers. "We boys used to swim here in nothing but our boxer shorts all the time and you never complained then."

Rose spun around in the water. "Right," she said. "Barbaric but true."

"I suppose you're out there in a full wetsuit, a handful of gillyweed at the ready," he said over the clicking of his belt buckle.

"No, just a plain old swimsuit. I won't tell you what colour though. You'll have to come catch me to find out," she said, smirking herself now. "Remember: to the shorts only. Nan has a strict no skinny dipping policy. Ever since George – "

He huffed at her sarcasm. "Don't worry. I'll keep it modest and decent. Nothing creepy."

"No, of course not," she said. "I'll try to think of you as any other aquatic mammal. They're hardly ever dressed. Maybe a selkie."

"No, not a selkie. Nothing that makes its home in icy northern water - argh - "

Rose whirled around again at the sound of a yelp and a hiss from Scorpius. He stood on one foot in the shallow water. "It's glacial!" he rasped.

He looked more lean and crystalline than ever, the ethereally pale skin of his legs, arms, and torso white in the dimming light, his limbs rigid, and his breath sucked deep into his lungs. He didn't bear much resemblance to any water creature Rose knew, which was all of them. Instead, he looked like a lightning bolt frozen in time just as it was about to shock the water.

But there was no thunder from him, only a stream of muttered complaints. The Malfoys were never ones to suffer in silence.

Rose laughed. "It's alright, deary, keep coming toward me. There's a good lad." She swam to where her feet could touch the ground again, walking toward him with one arm extended. "Let Rosie help you."

He inched into the water, one hand raised as if to protect himself. "Don't pull me in. I'm not ready."

"There's no getting ready, Scor," she cooed, as if luring a nervous creature. "If you plunge in to your shoulders all at once, you'll be fine."

"I will do no such thing," he said, grimacing like mad as the water seeped through his black shorts. "And don't splash me."

"Oh no, I wouldn't dare," she said. Her voice was low and soothing, but beneath the water she used her leg to sweep his, knocking him in.

Scorpius thrashed and yelled for a moment before she got hold of his hand and pulled him within arm's length of herself. He drifted beside her, growing quiet. "Blue," he said. "Your swimsuit is navy blue. And you've used a warming spell on the water. That's how you're so comfortable, lazing about in here."

She nodded. "Got me."

"You brought your wand in with you?"

"No, it's a wandless warming spell and it goes no further than my arms can reach. It's an old marine researcher's secret. I can teach you, if you like. Though it's best to start off learning it with a wand," she said. As she spoke she walked backward through the water, back to where it was deep and dark enough that she would need to truly swim. Scorpius kept close, keen on staying within the zone of warmth emanating from her.

"For tonight, I'll borrow from your spell, if you don't mind," he said. "I need to talk to you about other magic right now. You've made enough warm water for both of us anyway."

The light was low, dappeling the surface of the water, the sunset twinkling in Rose's eyes as she teased him a little more. "Are you sure you're warming up, Scor? You're not still glacialized? Your lips look a little blue."

As she said it, she made a playful grab at his chin and nudged his full bottom lip with her thumb. She hadn't meant to tip his mouth open and feel the warm wetness of its inner edge. She hadn't meant to, but it had happened all the same. It was too much, too intimate, not the kind of play that could go on between them now that they weren't children.

Scorpius seemed to be frozen again for a moment before his breath caught and he clipped his mouth closed. "Stars, Rose. I need you to not – I need you to be serious for a moment."

She gave a sharp nod, hiding the embarrassed flush in her cheeks, her hands both safely underwater now. "Yes. Sorry."

And then he was sorry that she was sorry. Swimming around her, Scorpius presented his back. "You're going to get tired, paddling away in the deep water. Hold onto my shoulders and keep me warm while I tow you around, like we used to."

"Tug boat!" she said, remembering this old childhood game.

"Yes, all aboard, and all that," Scorpius said. He was better prepared, but he was still a little breathless when she took hold of his bare skin, her hands closing over his trapezius muscles. He cleared his throat. "Right, tug boat's away."

Rose hummed, a child-like, delighted sound as Scorpius led her around the pond, her legs trailing languidly behind her. "I'm happy as a giant squid," she said.

Scorpius laughed through another scoff. "I thought giant squid were always angry."

She tsk-ed. "No, they're lovely. Highly intelligent too. And misunderstood as anything. Oops!"

Her grip on his wet shoulder had slipped, but Scorpius caught her hand and held it. "Let me have that tentacle then." He pulled her hand in front of himself, pressing her palm to his sternum, her elbow bending over his shoulder.

He must not have been used to swimming anymore, and under the water, his heart beat fast against Rose's hand. "Are you tired, Scor? Really, I can tread water for ages. You don't need to - "

"No, it's alright, madam cephalopod," he said, patting her hand. "I'm not tired, just – invigorated. And it's an honor to tow you anyway. Just relax, and listen to me."

With the repositioning of her hand, her face was closer to the back of his head now, close enough that with a slight lean she could have laid her cheek on his neck - his long, beautiful neck which, she remembered rather vividly, usually smelled so nice. If she didn't know better, if she could trust her own reactions, she might wonder if she was being romanced, or at least seduced.

But she did know better. This had to be nothing more than the baseline of tenderness that always existed between her and Scorpius, even when she was with Preston. It had been a problem. Maybe that was why in the days when she was with Preston, she hardly saw Scorpius. But none of that mattered today, and she let herself sink into their tenderness, resting her chin on his cool, wet shoulder.

He was clearing his throat again. "So Percy gave me a case study to read, one of his own. It was on a complex pregnancy preservation spell called Gravida Sympatico…"

He explained the spell, how two expectant couples, bound to each other by tenderness, tragedy, and trust could magically share their pregnancies' vitality when one of them was threatening to terminate. It was a lovely idea, but Rose had no idea why they were talking about it.

"I'm not pregnant, if that's what people think I've been hiding all summer," she said, still speaking over Scorpius's shoulder as they swam through the twilight together. "I've never been pregnant."

Scorpius drifted to a stop, keeping his hold on Rose's hand as he turned to face her. "I know, but someone's been pregnant with you," he said. "The couples in the case study were anonymous, known only by their initials. DM and AG, and CW and HG."

Rose's treading faltered and she sank a little. Scorpius was standing on his toes on the bottom of the pond, and he closed an arm around her waist to support her.

She took his arm, hugging it to herself. "That's them. Our parents. Us."

"Yeah," he said. "Percy was there himself when it was cast. It was an emergency situation, very tricky. He says he's not sure any ordinary set of witches and wizards could have pulled it off but…"

"But our parents are not at all ordinary," she finished.

Scorpius told her the details, how the plan had been to save him but it got flipped around once she was in danger.

"And in the end we saved each other?" she asked when he was finished.

He sighed, his breath forceful enough to disturb the water around them. "Something like that. Percy is still trying to sort out what happened, exactly, in case we can learn something to help other families, ordinary families who need a hand."

Rose was frowning. "I hate it. How could our parents get together and decide to risk your life like that when you were already so weak?"

His arm tightened its hold on her. "It's like you said. I was fading away anyway. If they hadn't done it, we'd both be lost. No, if I had the power to volunteer myself for it, for you, I would have done it all the same."

"Scor," she said, squeezing his arm, bowing her head into his shoulder. "Aren't you a darling? And I wish I had something to add to help with your research, but I really can't say how any of it happened. Hearing this is a bit overwhelming, frankly. I suppose I can't be anything but glad such a spell exists, and that it works. I owe my life to it, and the life of my oldest, dearest friend."

Scorpius withdrew his arm from around her waist, sliding it through her hands like an escaping sea snake. He threw himself into a backward stroke, away from her. "And there it is," he said. "What the researchers want to know is how the spell affects us now, as adults. They've been monitoring other Gravida Sympatico babies and the results have been mixed."

Rose waited, treading water again.

Scorpius said nothing.

"What results?" she prodded. "Is it dangerous? If it is, just say it. Someone should have told us years ago."

He sighed again. "No, the babies have all grown up to have close relationships with each other, but that could be down to their parents being close friends to begin with. It confounds things. What we do know is that the closeness isn't all the same. Some pairs are like siblings and others – they're like spouses."

Rose felt the warm water around her surge hotter. "Spouses," she echoed.

"Yeah," Scorpius said.

She waited, but he remained speechless. "Scor?"

He gulped a breath and dipped his entire head under the water, vanishing from sight, reappearing seconds later, his face breaking the surface, white and streaming, his skin and hair shining in what was now moonlight. He shook his head and smoothed his hair from his forehead with both hands.

Rose swallowed hard.

"So do I feel like a sibling to you?" he asked as he caught his breath, labouring to keep it steady and even now that he'd swam out of range of her warming spell. "Do I feel like another Hugo to you?"

"That's not how siblings work, Scorpius," she snapped, something strangely like anger in her voice. "My dad has loads of siblings and he loves them all in their own way."

He gave his head an almost violent shake. "You're stalling. You know what I'm asking."

"I am not giving any answer until I know yours," she said.

"Are you sure?"

"Yes."

"I can't take it back, Rose."

"Then don't."

"I'm in love with you," he said, blurting the words and standing panting in the cold water. "I don't know when or how it started. It's just always been that way. And before you leave this hideout and go back to London where someone new will fall for you, I had to tell you. I'm not demanding you do or say anything. But you have to know."

Over two arms' lengths of water, they faced each other, their colour high, breath fast. Rose shut her eyes, centring herself. And when she opened them again, she began. "I have questions. If you say you've always been – this way – then that means when you told me you weren't bothered when I went to the school ball with Orrin Phelps instead of accepting your mercy invitation – "

"It was not a mercy invitation. And I was lying. I was devastated you went with Phelps instead. Asking you to the ball was nothing but me acting on being in love with you."

Even though she was hearing him say the words a second time, they shook through her all the same. Without her knowing or planning to, she was paddling slowly closer to him. "And when we were still little enough for you to be fighting with your dad about whether you'd play quidditch, and you told everyone on the pitch the only way you would fly was tandem with me – "

He was moving toward her himself. "Yes, that was me already in love with you, way back then. To this day, the only thing that makes that ridiculous sport worth the bother is being with you."

She caught her breath and went on, fighting to ask after what she needed to know. "And when I needed a dress for Teddy and Victoire's wedding, and Mum was out of the country, and no one but you would come shopping with me, and you were no help at all because you raved and loved everything I tried on – "

He was close enough now to be back in the warm water of her spell. "Yes, what I really loved was you. Seeing you, following you. In everything, everywhere. I could have found you tonight in a wetsuit with gillyweed flippers and gills and I'd still be standing here telling you how deeply and persistently I've always been in love with you."

Her face was serious and she stopped in her advance. "And when you went to healer college and started dating that tall, elegant, brilliant woman – "

"That was me fighting to move past being in love with you out of respect for you being in love with someone else at the time, and maybe forever," he said, his voice low, his hand drifting up to reach for hers. "I had to try, Rose."

She propelled herself forward, his outstretched hand finding her waist, her fingers raised to touch his face, a tremor in her hand, feeling over the contours of his jaw and cheekbone, as if she was blind and reading his face. "And when your mother died, and I went home with you when you were sent for, and we sat together in her big armchair in the library, and I held you until you wept yourself to sleep – "

He turned his head, whispering his reply into her fingertips. "Great stars, Rose, what gave me any hope of ever being happy again was the fact that, even through that agony, I knew I was still in love with you."

"Scor..."

She kicked her feet, rising out of the water. He caught her, both arms around her waist, and she held his head, and kissed him. His response, the length and angles of his body were perfectly familiar and shockingly strange all at once. She had indeed known him forever, but not like this. His taste was like his smell, something to be smothered and lost in. His lips were soft and full beneath hers, but his kiss was well-formed, insistent, ecstatic. It only made sense to let him lead, after all his waiting, and she played her part of opening to him, reeling and clinging to him as he loosed his years of longing for her into a single exquisite kiss.

To fight the movement of the water, pushing them apart, in the same instant she brought their mouths together, she wound her legs around his waist. He swayed as he held her, cold hands on her warm back, skin to skin on the band of bare flesh between the bottom and top of her functional, almost prim swimsuit. She cupped one hand on the back of his beautiful neck, hers to nuzzle and admire all she liked, along with everything else there was to him, in time. All of him would be hers to love, and knowing it felt like the end of a painful struggle, the end of resisting what was inevitable.

Only it wasn't inevitable.

She broke from the kiss, breath ragged, speaking even as Scorpius followed her retreat, his lips still gently tugging at hers. "Scor, it's not because of the Gravida spell," she said into his mouth. "I chose this. I don't need to be enchanted to want you, to be in love with you – "

It was the first time she'd said it and he lunged upward to devour her kiss again, pulling her deeper into the water. Her heart felt stoked with love for him, like a furnace. It's rhythm was fast and powerful, thrumming with magic. But she still wouldn't believe it was the effect of some old spell their parents had got up to. This feeling, all its passion and affection, was for him. He belonged to her independently of anyone else. She let her hands trail down his face and neck, over his chest and the tight sides of his abdomen as he gasped into her mouth. She received it with a smile. This precious crystal miracle of a man was somehow mad for her, and she had never dared hope it could be true.

He tipped away from her only when they heard thunder rolling from somewhere far behind the hills in the west. "I could die happy like this, but we'd better get out of the water soon anyway," he breathed.

She laughed softly, lowering her face to his neck. "I mean it, Scor. I'm not snogging you as my favourite person on earth in my favourite place on earth because of some antenatal enchantment. Though I can see how you might need one – "

"What?" he said, shrugging to raise her head from his shoulder, craning his neck to look into her face.

"Really," she said, the remains of a laugh still in her voice. "Look at us. The mismatch in size and style, in background, everything. Who would ever believe you were with me? Have you noticed how whenever we eat out together, the servers always bring two cheques? And who could blame them when you're sitting there next me all stately and manicured and tall and gorgeous. Everyone must assume I'm your rough, frizzy little cleaning lady."

He tossed her body lightly, jostling her against himself as he held her in the water. "Enough, Weasley. They certainly don't think that. And if they do, they've got everything completely backwards."

"It's fine with me if they think I don't deserve you," she said, pressing a kiss under his ear, a new sensation that forced his breath out in a rush. "I rather hope they do think that. It will make them realize how incredibly special I must be to be with you in spite of everything they think they see."

Scorpius gave another scoff, his last of the night. "Well, I won't have it. I'll get you something to let everyone know you're my soul-mate, spell-induced or not."

"What, like a quidditch training camp uniform? A T-shirt I can wear that says 'Property of Scorpius Charles Malfoy'?"

"I do like that, but no," he said, his forehead pressed against hers. "I was thinking of something both more and less subtle. Something like a ring. One of those massive Greengrass emerald rings my mother used to wear."

"A ring? Scorpius, it's our first day together – "

"I know, but – "

"How about we start with a more conventional activity for a new couple than exchanging rings?" she said.

More thunder rolled in answer. Scorpius looked away from her, watching the horizon for lightning. "You mean, like not getting electrocuted together in a quaint little pond?"

Leaving her arms around his neck, Rose rearranged her legs so he could hold her like a bride and begin their return to the shore. "Oh, alright," she said. But I also want a date. A boring, civilized first date for tomorrow night, if you can manage it."

"You know I can manage it," he said. They were far enough out of the water for him to be holding her with his own strength alone. She was impressed he could do it so easily, but said nothing as he carried her back to dry land as if he was her hero.

"Tomorrow night," he said. "I'll be at your flat right after work with dinner reservations and freshly cut flowers – and emeralds."

"Scorpius," she tsk-ed as he stood her on her feet, summoning her towel and engorgio-ing it to a size large enough to enfold both of them at once.

"Fine, just a little emerald," he said as she wrapped herself in the towel with him, fluffing his usually perfect hair into the chaos she liked best. His hair was mussed, cheeks flushed, lips bruised. He looked like she had already thoroughly corrupted him, when she had hardly got started.

He gathered the towel around her face, tucking her damp, ginger hair into it, keeping her warm. "I'll bring you one secret emerald to wear hidden, if you like. Closed up in a locket, against your heart." He tugged on the towel to bring her lips to his again as he told her, "Wear it just for us."