The steam from the werewolf's snout had not dissipated before Harry Potter suddenly realized immediate action was imperative.

"Sir! Professor!" Harry yanked at the flowing sleeve of Snape's robes. "You have to get him back! Hurry! Please!"

The Potions Master stared at the Gryffindor in absolute incomprehension. "To whom are you referring, Potter? Lupin? I assure you, he will not revert before moonfall - "

"NO NO NO!" Harry shouted desperately. "Wormtail! Pettigrew! You have to get him back! He's the only proof we have that Sirius didn't kill all those people that he was sent to Azkaban for!"

Severus Snape snorted. "A dead rat is hardly conclusive evidence of a convict's innocence before the Wizengamot."

"PROFESSOR! WORMTAIL BETRAYED MY PARENTS TO VOLDEMORT! HE WAS THE SPY! HE WAS THEIR SECRET-KEEPER!" The boy screamed the words into Snape's face, not caring that tiny drops of spittle landed on the man's pale cheeks.

"WHAT!"

 "You were unconscious in the Shrieking Shack when Lupin and Sirius got him to confess! YOU HAVE TO GET HIM OUT OF THERE - " Harry shrieked, frantically pointing to the panting werewolf, whose glowing yellow eyes narrowed at the teen's wildly-waving arm.

Snape whirled to face the black dog as it transformed into the tattered figure of Sirius Black.

"Harry speaks the truth," Sirius said simply. "I persuaded Lily and James to switch Secret-Keepers, and none of us knew that Peter was a Death Eater. It's my fault - "

"JUST GET HIM OUT, SNAPE! THERE MAY BE TIME TO SAVE HIM! WE HAVE TO SEE HIM PUNISHED FOR KILLING MY MUM AND DAD!"

At the mention of Lily Potter, Snape's wand hand rose, pale in the moonlight, but empty, as he extended it toward the convict. "Give. Me. My. Wand."

Sirius slapped the stolen length of teak into the Potions Master's hand, and strong bonds instantly emerged from the tip of the wand, flinging themselves around the matted, furry body of the werewolf, who growled, then howled loudly enough to split the heavens. The transformed Remus Lupin struggled momentarily, then toppled to the ground, flailing on his back within the bindings of Snape's Incarcerous Charm.

"Great!" exclaimed Harry, and he would have rushed toward the downed beast, had Snape not restrained him by grabbing his shoulder.

"Potter!"

"Hurry!" Harry urged. "Get Wormtail out!"

Severus Snape shook his head. "He's almost certainly dead. And even if we could revive him, he would be contaminated by the werewolf's bodily fluids."

"But we have to TRY," begged Harry. "PLEASE!"

Sirius looked as if he wanted to say something, but refrained at the last second, sensing that their best chance to persuade Snape to act lay with the three students.

Hermione Granger moved forward, followed closely by a trembling Ron Weasley. "Every second counts, Professor," she said firmly. "If there's any chance at all..."

Gritting his teeth against the desperate faith that the idiotic Gryffindors seemed to have in his abilities, Snape whipped open his robes and withdrew his ever-present Potions pouch. Quickly, he selected a vial of reddish-orange liquid, waved his wand, and the liquid solidified slightly into an elongated, gelatinous pill large enough to dose a Hippogriff.

"How are you going to get that into him?" asked Ron, his gaze alternating between the orange pill and the thrashing werewolf.

"Carefully," replied Snape, conjuring a pair of oversized dragon-hide gloves. "Stand aside, all of you."

Silently, he cast Impedimenta, which served to slow the werewolf's movements, then he hovered the large pill vertically over the supine beast's head. The Potions Master waited a couple of seconds until the werewolf emitted an enraged howl, then Finited the Hover Charm, allowing the pill to drop straight down into the animal's gullet. Another quick flick of his wand caused the werewolf to gulp and swallow, and the corners of the horrid, slavering mouth began to leak a purplish foam.

"What will the pill do, Professor?" asked Hermione.

"The potion forming the pill is an emetic, Miss Granger," replied Snape. "Hypothetically, it will cause Lupin to vomit up the rat. The potion tastes extremely bitter and acts as an internal irritant, and his digestive tract will do all within its power to get it out of his system."

Harry frowned. "You don't sound certain that it will work. You couldn't just conjure Wormtail out of him?"

"Not without risking conjuring out Lupin's stomach in the bargain," Snape returned with a sneer. "I'm not as skilled in internal medicine as Madam Pomfrey. My doubts about any success concern the dosage itself. A single swallow is sufficient to cause a mere human to purge, but I can only hope that the entire vial will be powerful enough to cause a reaction in an animal as large as the werewolf."

"LOOK!" shouted Ron, pointing at Lupin. "There he goes!"

The werewolf groaned and heaved, its body convulsing spasmodically. After gagging several times, the beast "uuurrrrrped" loudly and a sodden, limp rat suddenly splatted onto the moonlit grass.

"Stay BACK!" ordered Snape as the Gryffindors rushed forward in triumphant eagerness.

He Summoned the lifeless rodent a safe distance away from the werewolf, knelt down beside it, and - cautious to touch it only with the sturdy, dragonhide gloves - used a drying charm before attempting to revive the rat, repeatedly alternating "Ennervate!" with physically palpating the rat's chest and abdomen.

The moon rose higher and brighter as Snape worked, convinced he had been conned into performing a fool's errand - and wouldn't all of Gryffindor glory in that fact! - until suddenly, the rat convulsed under his hand, and it spewed up a foul liquid which spilled disgustingly over one of his protective gloves. Presuming that at least part of the rat's regurgitation would be some of the internal fluids from the werewolf's stomach, Snape quickly Scourgified the glove before casting another "Ennervate!"

The rat trembled and gasped for breath, shuddering uncontrollably beneath the onlookers' awed gaze.

"You did it," whispered Harry. "You really did it! Thank you, Professor!"

Severus Snape sat back on his heels, an uncustomary nonplussed expression on his face. "I would not have bet a single Knut on achieving success, Potter." He shook his head. "And I can only state that I hope you are correct in your belief that Pettigrew is the true criminal. I did not do all of this on a senseless whim, you do realize." He glared black fire at the grungy convict standing beside Harry. "I sure as hell didn't do it for YOU."

Sirius clenched his rotting teeth to avoid retorting, settling for a short, jerky nod of acknowledgment to the Potions Master.

"It wasn't a whim, Professor," said Hermione. "Sirius Black was wrongfully imprisoned for a crime - a bunch of crimes - he didn't commit. Now he can finally be acquitted, and the world will know the complete truth about what happened to Harry's parents."

Snape scowled. "We'd better get the rat to the castle, then," he muttered. "And the werewolf needs to be confined until sunrise."

"We'll take Wormtail to the castle," said Ron, looking around at the non-Slytherins for confirmation, and they all nodded eagerly. "You can shut Professor Lupin in the Shrieking Shack for the rest of the night. Is that okay?"

The Potions Master stared threateningly at the man in the grubby convict's clothes. "And you, Black?"

"I'll be accompanying the rat to Dumbledore's office, along with Harry and his friends. I'm not about to let him out of my sight again." Sirius ran his hand through his filthy hair. "Twelve years ago, I watched Peter transform and disappear down the sewers after he framed me for mass murder, not to mention for killing my best friends. I won't risk him escaping - not now, not ever again."

Something in the haggard man's voice convinced Snape, and he rose to his feet. "I'll meet all of you in the Headmaster's office." He pointed his wand at a stray twig, a remnant of the Whomping Willow's wrath, and transfigured it into a sturdy rat-sized cage. The resuscitated rat still lay weak and shaking on the grass, and the man in black used his wand to magically move the rodent into the cage. "Carry the cage by the handle only. Do not touch the rat. Do not come into contact with its drool, urine, or any excrement at all." He sighed unhappily, glaring at the students. "Really, you should stay entirely away from the cage. Knowing you three and your penchant for attracting disaster, I'd rather you just waited here until I return from the Shrieking Shack, and I shall transport it myself."

Sirius and the younger Gryffindors all looked at each other and nodded in unanimous agreement. "We'll be here, sir," said Harry, speaking for the group. The four promptly seated themselves a prudent distance from the rat cage.

Silently, Snape inclined his head and cast Petrificus Totalus on Remus Lupin's lycanthropic form. Once the werewolf was stiff as a door, he was easy to levitate and guide across the grass toward the opening beneath the undulating limbs of the Whomping Willow. Stilling the tree, Snape disappeared from view, the petrified werewolf drifting directly behind him.

-:- -:- -:-

The unlikely group ascended to Albus Dumbledore's office, where they took turns detailing the night's adventures, pointing repeatedly at the bedraggled rat in the cage.

Dumbledore fire-called the Ministry of Magic, who sent Aurors to take statements from all involved, and to witness the forced transfiguration of Wormtail into Peter Pettigrew, living proof that Sirius Black had, indeed, been framed over a decade earlier. At Dumbledore's insistence, the Aurors had waited until sunrise to initiate Wormtail's transformation, given the possibility that his human form might involuntarily transform into a werewolf while the moon still ruled the skies.

Weakened by his devastating experiences, Pettigrew himself could barely stagger as the Aurors took him into custody, Flooing away from the Headmaster's office. He didn't look back as the green flames flared, not to plead with Harry, not to beg favor from Ron. In his future loomed the Dementor's Kiss, and he now seemed silently resigned to his fate, which - given his undeniable lack of courage - was probably preferable to living the rest of his life as a werewolf.

Dumbledore, Snape, Harry, Ron, and Hermione stood staring at the cold fireplace for long moments after the Aurors and the Animagus had disappeared. Sirius had been granted leave to remain in Dumbledore's custody until his next hearing before the Wizengamot, and the ragged man sat slumped in a leather-upholstered chair with a carved-wood frame.

"I can't feel pity for him, you know," Sirius said quietly. "I just wish... I wish he could have been a better person, even when we were students."

Snape snorted. "I could say the same of you, Black."

"Let's not go into this now," Dumbledore ordered. "Pettigrew has been arrested, he'll be tried, convicted, and punished under the law. And Sirius, you'll have plans to make for your own future. At long last."

Sirius sighed. "Right now, I'd settle for a long, hot bath, a filling meal, a hot fire, and a glass of Firewhiskey. In that order."

Harry grinned as Dumbledore's blue eyes twinkled above his half-moon spectacles. The Headmaster snapped his fingers and gave quick orders to the house elf who appeared in response to his summons. The elf bowed and disappeared, leaving Dumbledore to clap a gentle hand on Sirius' shoulder. "Your wish is being fulfilled as I speak, my dear boy. And I do hope you can take the opportunity to enjoy a good, long rest here in the castle."

Before Sirius could reply, there was a deferential knock at the outer door leading to the gargoyle-guarded spiral stairs.

"Enter," said Dumbledore.

Remus Lupin, looking rather the worse for wear, with new scratches across his face, slowly entered the Headmaster's office, his eyebrows rising as he viewed the assembled group. "I see that you're all here," he said quietly. "And you all know ... why I have come." He looked at Dumbledore. "I failed to take my Wolfsbane last night, Professor." The man's shoulders drooped in despair. "I transformed. I'm sorry to have let you down. I will formally tender my resignation later today, after I receive attention from Madam Pomfrey."

"Are you unwell, Remus?" Dumbledore asked kindly, concern showing in his eyes.

Lupin shrugged slightly. "It's just that my stomach is killing me. I've never before experienced this sort of discomfort as a result of transforming at the full moon. I don't understand it..."

He looked around at the odd assortment of knowing expressions which had greeted his statement. Puzzled, he spread his hands, palms up.

"What?"