A/N: This is the second chapter I meant to post yesterday. It's from Sirius's POV. Thanks for your patience, and enjoy!

...

Sirius tossed aside a rusty watering can. Beneath it lay a stack of old textbooks and after casting a Revealing Charm on them, he found nothing of import within. The books were tossed one by one behind his back into the ever-growing pile of rubbish. He'd taken to vanishing objects he found useless, but with Harry's second task related to fire, Sirius thought it better to leave the piles of rubbish as they were. Sooner or later, he'd bring Harry by and set the discarded items on fire and teach Harry how to extinguish or control magical fires.

Sirius worried that Harry would be challenged with Fiendfyre. While helpful for destroying horcruxes, Fiendfyre was destructive, lethal, and dangerously difficult to cast, control, or extinguish. Sirius had considered casting Fiendfyre upon the entire Room of Requirement, where he was currently looking for horcruxes. But without knowing if any horcruxes were inside, or which one lay within, he was reluctant to irrevocably destroy everything inside the Room. Nevertheless, ifand when he found a horcrux inside the Room of Requirement, he would choose that day to help Harry control and extinguish Fiendfyre, while killing a horcrux in the process.

For now, he sorted through thousands of discarded objects that generations of Hogwarts students had been stowing in the Room for centuries. He'd happened upon the Room of Requirement by accident, not realizing that's where he was. In one of his nightly jaunts around the castle as Padfoot, keeping his canine nose to the ground for any signs of trouble, he'd paced in the seventh-floor corridor, sure he smelled something off. The double doors to the Room appeared from out of nowhere and he entered, finding the source of the terrible odor to be a dying Mandrake, seemingly placed there in the last few days, if its leaves were any indication. From that moment, he'd scoured the Room of Requirement for any other hidden things, believing that Voldemort may have hidden something of his own in there.

It was the only part of the castle that didn't appear on the Marauders' Map. Sirius admitted that since the Chamber of Secrets incident two years ago, it was possible that other parts of the castle were missing from the Map, including the Room of Requirement. The Room had a description in Hogwarts: A History, but as Sirius and his friends never found it in their years at Hogwarts, they assumed it was as legendary and mythical as the Chamber of Secrets. Sirius tried adding the Room to the Map, but found the Room Unplottable, so it would remain another one of Hogwarts's many mysteries.

Outside his teaching responsibilities and spending time with Harry, Sirius devoted most of his waking hours to finding the horcrux that was at Hogwarts. Dumbledore was sure one was inside the castle, just as he was sure there was one at the Gaunt shack in Little Hangleton. Sirius and Remus had already tried retrieving the horcrux from Little Hangleton with no luck, as the enchantments on the Gaunt hovel were vicious and repelled them. They had no idea which horcrux was there, but given the aggressive, Dark magic around the old Gaunt home, there was no doubt in any of their minds that something as precious to Voldemort as his own soul lay inside.

Dumbledore showed Sirius a few key memories that supported his claim. First, Sirius saw the memory of Voldemort applying for the job of Defense Against the Dark Arts professor in the late 1960s. Crucially, Dumbledore had acquired the memory of a house elf called Hokey, whose memory showed a younger Tom Riddle visiting an elderly witch called Hepzibah Smith. Smith had Slytherin's locket and Hufflepuff's cup, both items which Riddle desired, and mere days after that visit, Hokey's memories showed that she was framed for the murder of her beloved Mistress. The job interview happened years after Voldemort stole the locket and cup from Smith and Dumbledore supposed that sometime before or after the interview, Riddle had hidden one of his horcruxes inside the castle.

Nothing remained in the Chamber of Secrets. The Slytherin common room and dormitories had been scoured over the last summer holidays by Dumbledore himself and he found nothing. Every inch of the castle was regularly inspected by Filch. It was by sheer dumb luck that Sirius found the Room of Requirement. Now that he knew it existed, he hoped that either Hufflepuff's cup or the heavy-looking black signet ring that Riddle wore in one of Dumbledore's memories was hidden somewhere in the Room.

To Sirius's displeasure, the Room was massive and contained thousands, if not tens of thousands of discarded things. Finding something as small as a ring – or even the comparably bigger cup – would take months, if not years, to locate. Nonetheless Sirius continued his search in his free time, hoping that one day he'd find what he was looking for, be it the cup or the ring.

Sirius rubbed his eyes after flinging away a dusty owl cage. He found an old chair and sat in it, taking a moment to rest before moving onto the next area for inspection. He wondered if the Room of Requirement held a different horcrux altogether, or if it held one at all and he was wasting his time, sorting through piles of student embarrassment.

Checking his watch and seeing that it was nearly time for tea with Harry, Sirius finished up his work in the Room and went to the double doors that led out to the seventh-floor corridor, keeping the Marauder's Map on him to ensure Harry wouldn't be around. Harry had taken to stalking the corridor after the run-in two weeks before. Sirius couldn't blame him, but he wanted Harry to focus on the second task of the Triwizard Tournament rather than the search for horcruxes.

Seeing that Harry was in his dormitory, moving down toward the Fat Lady's portrait, Sirius stepped out of the Room of Requirement and sped down to the Defense Against the Dark Arts classroom to prepare tea. He had just put the kettle on to boil when Harry walked in with a lumpy parcel in his hands.

"Why are you covered in dust?"

"I was cleaning," lied Sirius, seeing Harry's eyes narrow in suspicion. "Harry, we've been through this. I don't have to tell you everything I do. You don't tell me everything you do." Harry's cheeks flushed with color. "Is it just you today, by the way?" Harry nodded and Sirius pulled out two teacups for them.

Harry shuffled towards his usual armchair, placing the parcel on the seat and opening it to reveal an emerald garment.

"Green?"

"Is there a note?" asked Sirius, watching Harry take out the emerald dress robes gingerly. A piece of parchment fell to the floor and Harry picked it up, setting the dress robes back on the chair.

"Dear Harry, Molly insisted on the emerald because she says it's the best color for Ginny and would bring out your eyes. If you don't like them, I can figure something else out or try to talk Molly out of it. Love, Tonks."

"Try them on," Sirius suggested. "Just the robes – the dress shirt and tie shouldn't be a problem." Harry removed his school robes and tried on the emerald ones.

"How do I look?"

"Dashing. Look at yourself in the mirror!"

Harry turned around to look in the mirror. He gaped at himself and Sirius chuckled, sitting down with the freshly made cups of tea in front of him.

"Molly's got a good eye. Your mum always said she wished Slytherin had other house colors because emerald used to be her favorite color."

"She did?"

"I might've told Molly."

"You did?"

"That look on your face when I told you Tonks wanted to order you matching outfits led me to believe you didn't trust her," Sirius said, barking in laughter. "She might choose ridiculous colors for her hair, but she wouldn't have done that for your dress robes. She wanted you in navy."

"I like the green," Harry said quietly, feeling the fabric of the robes.

"Thought you might. Now why don't you put it away and we can start discussing that fire task you've been putting off?"

Harry reluctantly took off his dress robes and stuffed them into the opened parcel bag. He slumped into his armchair, sighing heavily.

"I have two months, don't I?"

"That's not much time to learn spells that you shouldn't be learning for two or more years."

"I wish I'd gotten the air task."

"I doubt Fleur Delacour will have an easy time with whatever she's given."

Harry didn't seem convinced by Sirius's reassurance. He turned away, looking into the fire in the office. "Can you help Ron find a date to the ball?"

Sirius choked on his tea. "Ron isn't going with Hermione? Is that why it's just you today?"

"Why would you think they're going together? They fight all the time!" Harry said irritably. "They were fighting when I left the common room and Ginny was trying on her dress in her dormitory."

Sirius bit his lip to keep from laughing. It was obvious Ron and Hermione fancied each other, just as it was with Harry and Ginny. Instead of spelling it out for his godson, Sirius said, "Maybe the fighting won't last forever. What about Miss Luna Lovegood? You're friends with her, aren't you?"

"Ron thinks she's loony."

"What do you think of her?"

"She's all right," Harry said, shrugging.

"What about the other Gryffindor girls in your year? Miss Patil or Miss Brown?"

Harry frowned deeply. "I don't know."

"How am I supposed to help Ron if I don't know who's available?" Sirius asked, laughing. "Besides, if Ron needs my help, he should come to me directly. Why doesn't he just ask his brothers?"

"They won't stop teasing him after he tried asking Fleur."

"She said no?"

"Obviously," Harry said, rolling his eyes dramatically. "She's going with some Ravenclaw bloke."

"Well, as thrilling as your dating lives are, we've got other things to get to," Sirius said, swishing his wand at a book on his desk. The book landed in Harry's lap with a thud.

"Magical Fires: A Pyromage's Guide to Managing Your Own Inferno," read Harry. "What's a pyromage?"

"A witch or wizard who enjoys magical fires," Sirius replied. "Wendelin the Weird was the first recorded one. She liked being burned at the stake so much she purposefully got caught so she could make the flames tickle her. Fire magic was how the Floo Network was invented, so it has its purposes."

Harry flipped through the pages, grimacing at some of the images of burned witches and wizards who had hurt themselves with their experiments.

"Fiendfyre's in here, too. Isn't that supposed to destroy horcruxes?"

"It is, but you don't need to learn how to cast it. If we have time, it'll be good for you to learn how to avoid it quickly. It's almost impossible to control, so I doubt the Triwizard task will have you fighting it."

"How am I supposed to learn this without setting the castle on fire?" Harry asked, peering over the book and his glasses. "Fleur can go up to the sky…Cedric can jump in the lake…and even Viktor can go underground, but what am I going to do?"

"I think I've got a place for us to practice."

"On the seventh floor?"

Sirius inhaled slowly and nodded. "Yes. There's a place up there where we can go, but I don't want you going until you've memorized all the spells in there, except for Fiendfyre."

Harry groaned and slammed the book against his forehead. "But I've got that essay on—"

"If you memorize everything, I'll give you a pass on the essay," Sirius replied, seeing Harry's face light up. "But you've got to get this done. We'll begin right after the Yule Ball." Harry winced and leafed through more pages of the magical fire text. Harry's forlorn expression brought a pang of pity into Sirius's heart and he cleared his throat loudly. "You know what, Harry? Let's go through all that together after the ball. We can wait a few more days."

Harry exhaled in relief, closed the book, and sat back in the armchair to sip his tea.

"By the way, has McGonagall taught you lot how to dance yet?" asked Sirius. Harry shook his head quickly and Sirius grinned widely in return. "Get on up, Harry. Time to teach you how to dance."

Based on Harry's expression, Sirius thought his godson was more willing to face a dragon than learn to dance with him. Reminding him that it was a good skill to have in case he wanted to impress Ginny, Harry blushed, and Sirius's grin became a smug smirk, knowing he'd trapped his godson into learning a valuable life skill.

…

"I'm telling you, I saw what I saw!" Harry said angrily, storming around the Room of Requirement with his hands in the air. "He's a Death Eater!"

"He was a Death Eater, Harry," Sirius groaned. "I hate Snape more than anyone, but he's on our side."

"How do you know?" Harry demanded, his nostrils flaring wildly only inches from Sirius's face.

"Dumbledore," Sirius said, through gritted teeth. "I'm choosing to trust him."

"Why?"

"Because we've got to trust each other. We can't do this alone, Harry, and neither can you."

"But his tattoo – it's the Dark Mark! Karkaroff had one too – they said it was getting darker!"

"I'm sure there's a perfectly good reason why Snivellus said that," Sirius growled, thinking of storming into Dumbledore's office with the same question.

"What's the reason?"

"I don't know, and I don't have to know everything. Neither do you."

"This is stupid."

"Not as stupid as it'll be if you neglect learning how to manage fires," Sirius retorted. "This is not the time to speculate on Snivellus. The less I hear of him, the better."

Harry glared at Sirius, his shoulders swung back as if he wanted to punch something, but Sirius stood firm. As angry as he was that Snape still had his Dark Mark and was showing it to Karkaroff in a place where Harry could see him at the Yule Ball, there was no convincing Dumbledore that Snape shouldn't be trusted. Sirius and Snape were forbidden from speaking to one another unless strictly necessary, following their physical altercation in October over the Triwizard champions. What had been brewing for months as passive-aggressive animosity spilled over into physical violence. Dumbledore and McGonagall decided Snape and Sirius should avoid each other whenever possible. With the Marauder's Map, that task was easily accomplished.

Avoiding Snape did little to assuage Sirius's suspicions that the "ex" Death Eater was truly on the right side of history, but as Dumbledore trusted him, Sirius begrudgingly tolerated his existence at Hogwarts.

Harry began setting fire to a series of objects in a row. Sirius watched as the flames rose as the objects became bigger, until finally, a wall of fire was erected between the two of them. They walked to one end of the wall, where the flames were the smallest and most contained.

"Extinguish only enough so you can walk through the wall," Sirius ordered. Harry concentrated his wand on the shortest section of the fire wall, but it only grew taller. "That's okay. Try again over here." Sirius moved a few feet to the left and Harry cast the spell again. The flames sparked outward, but Sirius contained them.

The process continued for the next hour as Harry tried to extinguish the entire wall of fire. Unbeknownst to him, Sirius kept the wall contained but slowly widened it to create an arc around Harry, challenging him as the flames enclosed him in a semicircle. Sirius expected the fire challenge of the second task to include escaping from seemingly inescapable fire; the better prepared he could make Harry, the likelier it would be he'd survive unscathed.

As Harry's spellcasting grew sloppier, Sirius began reducing the flames for him. By the time the flames were fully extinguished, Harry was sweating profusely and his face was red from exertion.

Sirius conjured a glass of water and handed it to him. Harry drank several glasses and set it down to place his hands on a broken desk, breathing heavily as his hands slipped with sweat. Sirius brought a chair for Harry to sit in and then he leaned back against the desk with his arms crossed over his chest.

"Not bad," Sirius concluded. "A little better than yesterday, but not by much."

"You're making it harder."

"The better you get at controlling the fire, the harder I'm going to make it for you."

Harry wheezed and dragged his robe sleeve across his forehead to wipe the sweat off his brow. "Do I still have my eyebrows?"

"Yes," Sirius said, chuckling. "Both eyebrows are fully intact." He hummed lightly to himself, conjuring a towel for Harry to dry himself off, and added, "Besides your misadventure with Snivellus and Karkaroff, how was the Yule Ball?"

Harry didn't meet Sirius's eyes. "Good."

"You looked like you were having fun on the dance floor with Ginny."

"That was nice."

"Ron took Lavender, I see?"

"He doesn't like her," Harry mumbled. "I don't, either."

"And Hermione went with one of the Beauxbatons boys?"

"I didn't know Hermione knew French," Harry said. "Or maybe I did and I didn't remember."

"Is that all, then?" Sirius asked, brow raised at his godson. "You had a nice time with Ginny, Ron didn't have a nice time with Lavender, and Hermione speaks French?" Harry nodded and reached for the empty glass on the desk. Sirius filled it with water and after seeing Harry take a few gulps, added, "Really? That's all you're going to say?"

"I don't have to tell you everything," Harry said coolly. "You don't tell me everything."

"No, but if you did anything after the Yule Ball–"

"No," Harry said, shaking his head abruptly. "It's not like that. No. No, no."

"I'd hope not, at your age, but I have to ask." Sirius leaned against the desk and put his hand over his mouth to keep Harry from seeing his mischievous smile. "Anyway, want to try the wall of fire again?"

Harry grimaced and buried his face in the towel. "I don't want to, but I know I should."

Sirius clapped his hands and created a new boundary for the wall of fire. Harry got up from his seat, sighing heavily, and began anew.

…

"How is Harry progressing with your training?" Dumbledore asked calmly. He offered a lemon drop, but Sirius refused it.

"Not…great," Sirius replied grimly. "He can walk through fire, extinguish a path through a wall, and his Aguamenti is passable. He's nowhere near ready to handle anything more than a bonfire."

Dumbledore pulled out three books and slid them over his desk. He commented, "The next task is six weeks away. These may help with defensive magic." Sirius flipped through one of the books, seeing many of the charms Harry was already learning. Some charms and spells were new, however, which gave Sirius hope that they'd be easier for Harry to master.

"Let's set this aside for now," said Sirius. "I'm tired of you dodging my questions about Sni-Snape."

Dumbledore sighed tiredly. "I'm not dodging any of your questions. I have told you what you need to know."

"He saw the Dark Mark. No one stops being a Death Eater, Albus."

"I have told you many times, Sirius," replied Dumbledore, shaking his head gently. "Severus is a double agent. He is a highly valuable spy and he risks his life to help us."

"And you have good reason to believe he's telling the truth?" Sirius grew more impatient by the moment. Dumbledore was infuriatingly coy at times; this was one of the moments in which Sirius felt he needed to know the truth, as badly as he needed air to breathe or water to drink.

"Yes. It's a personal matter between us," Dumbledore said firmly. "I have my full confidence in him and I trust him with my life."

"You know that doesn't make me feel better," Sirius growled. "It's not as if I can ask Snivellus myself."

"I recommend that if you do ask him, you call him by his given name." Dumbledore's piercing blue eyes were stern, making Sirius feel as if he was a sixteen year old being scolded for a prank gone wrong. Something flickered in Dumbledore's gaze and Sirius wondered if they were thinking of the same, near-fatal incident.

"Never going to happen," Sirius grunted. There was simply too much animosity between the two of them; Sirius knew he would never learn the reason why Dumbledore trusted Snape with his life.

"I did ask you to come in for another reason," Dumbledore said, returning to his usual calm tone of voice. "What do you remember of a woman called Bertha Jorkins?"

"Jorkins?" Sirius contemplated Dumbledore's question, recalling Bertha Jorkins as a student a few years his senior who was neither very bright nor very personable. "Nosy and unintelligent. Why do you ask?"

"She's gone missing."

"Missing?" Sirius said, taken aback. "When?"

"Recently," replied Dumbledore, lacing his fingers together pensively. "She worked for Barty Crouch Sr. for a few years, then worked with Ludo Bagman for the Triwizard Tournament. She recently transferred back to Barty's department - International Magical Cooperation - and only weeks later, she went missing."

Sirius sat forward in his seat, his elbows pressing against his thighs as he considered the news. "How long has she been missing?"

"It's been a week, if I'm not mistaken. She was due to send me a report," Dumbledore said, holding up a stack of parchments, "but it came from Barty instead, claiming that Bertha took a few days off for her health."

"Then she's not missing," Sirius said flatly. "She's ill."

"She didn't return from her days off. A friend of hers reported her missing after they missed dinner together a few days ago," Dumbledore explained. "Bertha hasn't been seen since."

Sirius pursed his lips. "Why does this matter? What's Bertha got to do with Snape?"

"Nothing…but she's involved with the Triwizard Tournament and knows both Ludo and Barty. She's missing."

"You think she's working with Bagman?" asked Sirius, finding the idea that vapid, senseless Bertha would get herself involved with betting on Harry's life or hurting him. He thought she was stupid, but not sadistic.

"I don't know," Dumbledore sighed. "I have no reason to suspect Barty, but I find it jarring that a woman who was working with the others on the Triwizard Tournament has suddenly disappeared."

"If you're asking if I think she's capable of espionage, high-stakes bets, or any other foul play," Sirius said slowly, "the answer is obviously not. I do think she's gullible enough to be hoodwinked…but by who?"

"That is the question I've been asking myself." Fawkes flew to Dumbledore's side and gently nipped his robe sleeve. He stroked the phoenix's brilliant scarlet plumes attentively, apparently lost to his thoughts. "Bagman was sentenced to two years in Azkaban in November. He confessed he had no accomplices. By all accounts, that seems true, but I wonder if Bertha's movement to Barty's department was a sign of her trying to distance herself from him."

"It doesn't make sense that Bagman was ever involved in something like this. He's a gambler," Sirius countered. "What if they're both pawns in this?"

"I fear the same," Dumbledore agreed. "I had hoped that you might shed more light on Bertha's character, but I must conclude she and Bagman are somehow involved against their wills."

"How does Voldemort get to both of them?" Sirius said, groaning into his hands. "And who is he going to get to next?"

"I'm afraid that, at best, I have only conjectures," Dumbledore replied. "As usual, I request your assistance in watching the castle."

"I'll keep my nose to the ground." With that, Sirius took the books on fire protection charms under his arm and stepped out of the Headmaster's office to plan the next training session for Harry.