The evening was slowly creeping up on Severus, and he finally arrived at his quarters, glad to have a moment's peace from proctoring exams all day. He checked his clock, then headed for his potions supply closet to grab a premade wolfsbane potion. Lupin should be arriving any minute for his next dose. It was required that werewolves take the wolfsbane everyday for a full week prior to the full moon, with a final dose the day of, just before sunset. It was a pain for Severus to keep track of the days, but thankfully, Lupin seemed to take his condition seriously and had always arrived on time to collect his potion. Severus grabbed a vial of a shelf and walked back out to his living space, sitting down in his armchair and summoning tea to wait.

Once he had his tea perfected, he took an appreciative sip before glancing at his clock once more. Any minute now, and Lupin would be knocking on his door for his required dose.

The ticking of the grandfather clock was louder than usual while Severus agitatedly took another sip of his tea. The damn man had been diligent all year long, of all days to forget, why the end of the year?

After another couple long minutes, Severus snarled under his breath as he set his tea down with a firm click before he snatched the vial of wolfsbane and stormed out of his quarters, marching his way up the stairs to Lupin's office. When he found Lupin, he would chew him out and force the potion down his throat himself. He knew keeping a werewolf on a tight schedule with a school full of children had been an absurd idea.

He arrived at Lupin's office and walked in without knocking.

"Lupin!" he loudly called out.

Even if Lupin had been in his quarters which were adjacent to his office, he would have heard Severus's call. Severus frowned when Lupin did not come running out of wherever he was hiding, muttering apologies for his forgetfulness. Severus huffed and walked further into the office, looking down at Lupin's cluttered desk. There were stacks of essays in the process of being graded strewn all over the desktop, along with an old, faded parchment Severus recognized immediately, and he stepped closer, leaning over the desk and narrowing his eyes down at what was clearly a map of Hogwarts.

"So, this is what Harry didn't want to tell me about," Severus muttered, turning the map slightly to have a better look at it. He could see all the students and professors moving about, and he instinctively searched for Harry's name, frowning when he did not see his son listed or his friends, though there were so many names all over, he supposed he could miss their names.

Then he saw Lupin. The name was moving quickly down a passage that Severus was very familiar with—it led straight for the Shrieking Shack.

Severus growled angrily before running out of the office. He shoved the vial of wolfbane in an inner robe pocket and ran down the hall. All year, he had questioned Lupin's loyalties, and he was determined to show the headmaster just how wrong it was to put their trust in the likes of werewolves. He tried not to think prejudicially, but his past experiences taught him that werewolves were too dangerous to be around a school. And worse, Lupin was hired around the time Black escaped Azkaban. There was no way it was coincidental.

Severus exited the castle and headed for the Whomping Willow, summoning a stick that he then sent flying toward the small knot on the tree trunk, stilling the flailing branches. He carefully stepped down into the tunnel that would lead him to the Shrieking Shack, his wand ready. He slowed down enough so he could survey every nook and cranny, being mindful of each bend there was, leading with his wand before stepping further down the tunnel.

A sudden warmth grew in an inner robe pocket, and Severus leaned back against the wall of the tunnel while he dug into his pocket and pulled out his family bond ring, the eyes of the peacock glowing a red hot. Severus had a sinking feeling he knew what this was about and quickly cast a locator charm on Harry Potter.

The slightest tug of his wand pointed him onward into the tunnel. Apprehension now clawed at Severus gut like a vicious cat as he continued down the tunnel, leaving him feeling slightly nauseated. He had been completely prepared to face Lupin and a potential convict in the Shrieking Shack. He was not prepared for his son to be in the mix of everything, though what on earth Harry would be doing out here when he was supposed to be safe in the castle was beyond him.

Finally, he found a stairway and climbed with slow and calculated steps, keeping his wand in front of him. He could hear talking, and his heart nearly froze when he heard Harry's voice, and he hesitated, his eyes widening.

"What sort of animal?" Harry asked, though Hermione quickly cut him off.

"That was still really dangerous! Running around in the dark with a werewolf! What if you'd given the other the slip, and bitten somebody?"

"A thought that still haunts me," said Lupin. "And there were near misses, many of them. We laughed about them afterwards. We were young, thoughtless; carried away with our own cleverness."

Severus inched further up the stairs as he listened to Lupin talk about his guilt regarding not telling the headmaster about Sirius Black being an animagus and how "Snape's been right about me all along."

"Snape?" Black's voice cut through the air like a knife, and Severus grit his teeth, his knuckles white as he clutched his wand. "What's Snape got to do with it?"

"He's here, Sirius," said Lupin heavily. "He's teaching here as well."

There was a pause, and Severus took another step up the stairs, stopping when the stair creaked slightly under his weight. Lupin was telling the Golden Trio the story of how Black had tricked Severus into following Lupin down to the Shrieking Shack, and how James Potter had stopped Severus just in time. Severus took a few more steps up the stairway, and he could almost see into the room. Just a few more steps.

"Snape glimpsed me, though," Lupin continued, "at the end of the tunnel. He was forbidden to tell anybody by Dumbledore, but from that time on, he knew what I was."

"So that's why Professor Snape doesn't like you," Harry said slowly, "because he thought you were in on the joke?"

"That's right," Severus sneered from behind Lupin, and everyone jumped and turned to look at where he was standing in the doorway, his wand trained directly on Lupin, whose wand flew out of his hand. "You're wondering, perhaps, how I knew you were here? I've just been to your office, Lupin. You forgot to take your potion tonight, so I took a gobletful along. And very lucky I did . . . lucky for me, I mean. Lying on your desk was a certain map. One glance at it told me all I needed to know. I saw you running along this passageway and out of sight."

"Severus," Lupin began, but Severus stepped into the room further, keeping his wand on Lupin.

"I've told the headmaster again and again that you've been helping your old friend Black into the castle, Lupin, and here's the proof. Not even I dreamed you would use this old place as your hideout."

"Severus, you're making a mistake," Lupin said urgently, most likely trying to save his own skin. "You haven't heard everything—I can explain—Sirius is not here to kill Harry."

Severus made sure to place himself between the two criminals and the three students cowering on the other side of the room. He would not allow either of these men to hurt his child if he could help it.

"Two more for Azkaban tonight," Severus said. "I shall be interested to see how Dumbledore takes this. He was quite convinced you were harmless, Lupin. A tame werewolf."

"You fool," Lupin said with a shake of his head. "Is a schoolboy grudge worth putting an innocent man back inside Azkaban?"

"I've had enough of this," Black snapped, and he lunged toward the kids—Ron and his squealing rat, specifically.

Severus quickly redirected his wand on Black, and the thin, crazy looking man stopped dead.

"Give me a reason," Severus whispered. "Give me a reason to do it, and I swear I will."

Black backed up a few steps toward Lupin and Severus kept them both glued to the spot as he debated his next best move that would safely remove the kids while keeping the two criminals in their place. Oh, how he had dreamed of being the one to capture Black and give him exactly what he deserved.

Before Severus could do anything more than snarl at Lupin and Black, Harry scooted around him and stood in front of the two unarmed men.

"Potter," Severus warned in a low voice, keeping his wand on the two men behind Harry. "Unless you have forgotten, Black has been after your skinny neck all year. I suggest, you stay behind me."

"I want to hear them out," Harry said. "They say there's more to the story, so I want to hear it. I want the truth."

Severus glared at his son, though he was unsure if he was feeling more fear or anger.

"Get out of the way, Potter," Severus growled through his teeth.

"No."

Severus took a step toward Harry, then froze and his eyes widened when Harry raised his own wand, pointed directly at him. Hermione and Ron gasped behind him, while Lupin and Black seemed just as surprised.

"Potter." Severus tone held disbelief. "Lower your wand this instant."

"Please," Harry pleaded. "I need to hear this."

"Harry, perhaps—" Lupin started as he took a step toward Harry, only to freeze when Severus angled his wand more on him.

"Do not move," Severus warned the two men before he leveled Harry with a stern look. "Lower your wand. You could face expulsion for this, boy."

"You said everyone deserves a chance to explain themselves," Harry said. "They do, too. No matter what they did before or even now."

Severus sighed heavily through his nose, lowering his own wand slightly. As much as he wanted to blast Lupin and Black across the room, he knew how much Harry had wanted to hear personally why Black betrayed his parents. And if there was more to the story . . . well, Severus wasn't sure how to feel about that. Still, he did not like that Harry still had his wand on him.

"Harry James," Severus said, "lower your wand."

Harry didn't obey right away, but slowly, he lowered his wand, and when it was low enough, Severus lunged forward and snatched Harry's wand away, tucking it into his wand holder in his sleeve, then he grabbed Harry's wrist and yanked him away from the two men, effectively placing his son behind him once more. He did not let go of Harry's wrist as he leveled his wand on Lupin and Black once more.

"Thanks to Potter's imprudence, you now have five minutes to explain yourselves," Severus said.

"Then it's time we offered you some proof," Black said. "You, boy—give me Peter. Now."

Peter Pettigrew? Was Black saying Pettigrew was alive? And that he was Ron Weasley's pet rat? Severus frowned as he watched Ron clutch the rat closer to his chest. Curiously, the rat was trying very hard to get away from Ron, scratching and biting at Ron's neck.

"Scabbers has been in our family for—"

"Twelve years!" Black said. "An awful long time for a common garden rat! And he's missing a toe!"

"So?" Ron said. "He probably had a fight with another rat or something."

"Just before he transformed," Black explained, "when I cornered him, he yelled for the whole street to hear that I'd betrayed Lily and James. Then, before I could curse him, he blew apart the street with the wand behind his back, killed everyone within twenty feet of himself, and sped down into the sewer with other rat after chopping off his finger."

"Harry," Black continued, looking at Harry directly, ignoring Severus's sneer. "I as good as killed them. I persuaded Lily and James to change to Peter at the last moment, persuaded them to use him as Secret Keeper instead of me. I'm to blame, I know it." His voice broke. He turned away.

"Enough of this," Lupin said, summoning his wand. "There's one certain way to prove what really happened. Ron, give me the rat."

Severus allowed Lupin, and only Lupin to walk over and take the rat away from Ron. He scruffed the squealing animal, holding it up in the air while it thrashed and twisted around. Finally, Lupin hit Scabbers with a spell, and the rat fell and hit the floor.

Severus released Harry's wrist and held an arm out, backing up Harry and Hermione from the transformation, while Ron scrambled back a bit on the bed he was sitting on.

Slowly, the rat transformed, growing a more humanoid head by the second while sprouting longer limbs, and in less than two minutes, a man was standing where Scabbers had been, cringing and wringing his hands. He was a very short man with thin, colorless hair, and there was a large bald patch on top of his head. He twitched and moved with a shaky gait, his eyes darting to the door and back again.

"Well, hello, Peter," said Lupin, "Long time, no see."

"S-Sirius . . . R-Remus . . ." Pettigrew said in a squeaky voice. "My friends . . . my old friends."

Peter suddenly darted for the door, but Severus flicked his wand and the door slammed shut with a resounding click. Peter scratched at it like a frantic animal before Lupin and Black grabbed his shoulders and threw him back to the center of the room.

"Friends?" Black hissed. "I would never betray my friends to Voldemort! How could you?"

"I didn't mean to!" Pettigrew confessed. "The Dark Lord, you have no idea the weapons he possesses! Ask yourself what you would have done, Sirius!"

It was then that Severus realized the whole story being pieced together in the room was true. Only followers ever called You-Know-Who the Dark Lord. All this time, Sirius Black had truly been innocent, and the man responsible for Lily's death stood before them—having hidden himself away as a pet rat—a free man.

"Died!" Black shouted. "Died rather than betray my friends! And you should have realized, Peter, if Voldemort didn't kill you . . ."

"We would," Lupin concluded.

"No, please, you can't," Pettigrew pleaded, then he eyed Ron and ran over to him. "Ron! Haven't I been a good friend? A good pet? You won't let them kill me, will you? I was your rat . . ."

Ron was slowly drawing back in disgust, so Pettigrew turned his eyes toward Harry, and he dropped to the ground and crawled toward the boy. Severus fixed his wand on the short man and kept an arm out protectively, keeping Harry and Hermione behind him.

"Harry," Pettigrew whispered, his hands outstretched, "James wouldn't have wanted me killed . . . James would have understood, Harry . . . he would have shown mercy . . ."

Black and Lupin seized Pettigrew's shoulders and threw him backwards onto the floor. He sat there, twitching with terror, staring up at them. Lupin and Black turned their wands on him, but before either could say a word, Harry wretched himself away from Severus and ran over to Pettigrew.

"Don't kill him!" Harry said. "Please."

"Harry," Black said, "Think about what he did."

"I know what he did. He can go to Azkaban. If anyone deserves that place, he does."

"Bless you, Harry," Pettigrew said, groveling at Harry's feet, clutching his robes.

"Get off me!" Harry yanked away from the man. "I'm not doing this for you. I'm doing it because I don't reckon my dad would've wanted his best friends to become killers."

"You're the only one who has the right to decide," Black said. He smiled softly at Harry. "You are so like your father."

Harry smiled back, and Severus stepped forward and grabbed Harry's arm, pulling him away from Black.

"We should head back to the castle," Severus said. "Clearly, there is much to be discussed with the headmaster and, preferably, a few aurors present. As much as I'd love all three of you to see a dementor's kiss, I suppose one will suffice. Lupin, if you would see to Mr. Weasley. Ah, yes, and before you do, take this."

Severus held out a vial, and Lupin's eyes widened before he snatched the vial and chugged it quickly. With the werewolf drugged and everyone assisting each other back through the tunnel with Sirius keeping a wand on Pettigrew, Severus kept a hold of Harry's arm and pulled his son along, pausing only to whisper in Harry's ear, "When we return to the castle report directly to our quarters."

"But I want to see . . ."

"No. Directly to our quarters. I will inform you of what happens when I return."

Harry huffed but allowed Severus to continue dragging him down the tunnel.

Suddenly, a hand tried to grab Severus's wrist to pull him off of Harry, but Severus tightened his hold and spun, wand pointed at Black.

"You can unhand him, now," Black growled. "I have Pettigrew under control. He's not some toddler that needs to hold hands with his teacher."

"Then perhaps he shouldn't act like one," Severus said, ignoring the red tinge at the tip of Harry's ears.

Black lunged forward again, reaching to remove Severus's hand, but Severus pulled back just out of reach.

"Watch yourself, Black," Severus said. "You may be innocent, but you are still an ex-convict. I have every right to keep you from laying a single finger on the students."

"Harry isn't just a student. His parents named me his godfather—his guardian in the event anything ever happened to them. And I plan to step into that role for him."

Harry's eyes widened at that while Severus's glare deepened, and he ignored the small spike of fear in his chest in favor of snapping at Black.

"No one in their right mind would dare put a child in your custody, not after the 12 years you spent in Azkaban. Enough of this, anything else you wish to say, you may do so in front of the headmaster."

Severus led the way down the tunnel once more, trying to calm his fuming mind. He felt Harry pull against him slightly.

"Sir, please," Harry muttered.

"Enough, Potter," Severus said. "Do not test my patience right now."

Harry fell silent once more, glancing back at Black, who smiled softly at him. Severus tried not to feel any bit of jealousy at the small interaction. He was not losing his son to this convict. He would fight tooth and nail to keep Harry. Of course, Black would have to be declared innocent and be formally released from Azkaban before anyone would even consider allowing him to apply for guardianship. Severus realized that in the end, no matter how it panned out, he would have to tell Black about his relationship with Harry. He smirked as he envisioned Black's reaction to that news.

Finally, they found the exit to the tunnel and stepped out into the slowly darkening sky. Severus paused as he watched clouds part, revealing the full moon. He gestured for Ron and Hermione to come to his side, and Lupin helped Ron lean his weight against Severus before he fell over and writhed, his limbs twisting and reforming.

"Oh my," Hermione gasped. She looked away. Sirius and Pettigrew watched on sympathetically, recalling the many nights they stayed with him during these transformations. Lupin's head slowly lengthened, along with the rest of his body. Hair was sprouting everywhere, and his hands slowly curled into paws.

Finally, there was a low whining, and a large wolf stood in Lupin's place, and his eyes slowly focused on Severus and the three students before glancing at Black and Pettigrew. Lupin whined submissively.

"The potion worked," Hermione remarked, awe creeping into her tone.

"Of course, it worked," Severus growled. "I brewed it."

Lupin glanced back at Severus, then at something over Severus's head. He whimpered, tail tucked, and he backed away slowly.

There was a coldness in the air, like all the life around them had been sucked away in a winter breeze. The clouds darkened once again, and Severus turned to face hundreds of dementors swarming directly for the group.

Black paled and jerked back slightly, and the distraction was enough for Pettigrew to shove Black to the ground before he dove for Lupin's dropped wand, transforming back into a rat and taking off.

"Oh, no you don't!" Sirius shouted, transforming into a dog and chasing after the rat.

"No, don't!" Harry called after Black.

Severus waved his wand, sending his doe patronus to chase off the dementors, keeping a tight circle around himself, the Golden trio, and the still wolf, who howled in concern as he watched Black chase Pettigrew toward the Forbidden Forest.

Black was so close, one more leap forward and he would land on Pettigrew and rip him to pieces. He stretched out his neck, then yelped as a dementor swooped past him, startling Black, who tripped and stumbled over a rock, hitting his head. Black fell to the ground, transforming back into Sirius. The wolf howled before daringly stepping out of the protective circle the doe had created, only to back up when three dementors swooped toward him.

Severus wasn't particularly sympathetic as he watched dementor after dementor feed from Black's soul as the man lay unconscious just with the trees of the forest. There was little he could do that didn't involve putting the kids at risk, and they were his first priority.

Harry, however, had other ideas. He managed to steal back his wand from Severus's sleeve, yanking it away before he ran out of the doe's protective circle and ran straight for Black—amidst hundreds of dementors. He reached out for Harry but was too slow to grab him.

"Harry!" Severus shouted. "Get back here!"

"Harry, no!" Hermione screamed. "You know what they do to you!"

"Come back, mate!" Ron shouted.

The wolf howled again.

Harry raised his wand, pointing it directly at the dementors flying above him.

"Expecto Patronum!" Harry screamed, and there was a bright flash of silver before a small fawn leapt into the air, bright and bold, chasing away several of the dementors, creating an even larger protective bubble than Severus's doe had.

The fawn circled Black a few times before leaping toward Severus's doe, touching noses briefly before the two leaped around together, creating one, large protective sphere that shielded everyone from the retreating dementors.

Within the protective bubble, Severus ran for his son, who was swaying on his feet. He caught Harry just in time as the child collapsed, and he held his son in his arms as Hermione, Ron, and the wolf ran up to him as well, looking down at Harry with concerned looks.

"It's a fawn," Harry whispered in a hoarse voice, "to go with your doe. Did you see?"

"Yes, I saw," Severus said, brushing a few strands of sweaty hair out of Harry's face. "You did very good. I am so proud of you."

Harry smiled at that, then at the wolf that gave him a small nod with a huff. Then, the world went black for Harry, and he closed his eyes.

Severus continued to hold Harry, feeling his forehead with his palm then the back of his hand.

"Is he okay?" Hermione asked.

"He's alright," Severus said. "Merely exhausted."

"What about Black?' Ron asked. "And that Pettigrew?"

Severus looked over at Black. The wolf was gently touching his nose to Black's chest, but he could see the man breathing, and he knew Black would live. Lucky him. Pettigrew, however, was nowhere to be seen.

"He got away, didn't he?" Ron concluded. "I can't believe I let him sleep in my bed with me."

Severus lifted Harry into his arms, then glanced up at the sky. The dementors were gone. The doe and fawn appeared on either side of him, and they both looked up at him. Severus was surprised Harry's fawn was still around even as Harry was unconscious. He nodded toward Black and Lupin.

"Keep them safe while I take the kids to the infirmary. I will send aid."

The deer nodded, then walked over to Black and the wolf, lying down next to them.

Severus adjusted Harry in his arms, then waited while Hermione assisted Ron before they slowly made their way to the castle.