Enter Professor Snape

"They've— got— a— right— to— know— everything!" Lupin panted, trying to restrain Black as best as he could. "Ron's kept Peter as a pet for years! There are parts even I still don't fully understand! And most of all, you owe Harry the truth!"

"Fine," snarled Black. "You get to keep Peter until the story's over— just keep a good grip on him so that he doesn't scurry off like the coward he is."

"You're nutters, both of you," said Ron shakily. "I've had enough of this. I'm off."

"There's a big hole in your story," said Hermione, regaining some confidence now that she was somewhat sure she wasn't in immediate danger. "The ministry keeps a register of all Animagi; names, animal forms, distinguishing characteristics. I did my homework; there aren't many of them, since it's such a dangerous process becoming one. And I think I'd remember if I saw Potter in the list; Pettigrew and Black certainly weren't in there either."

"That's right, Hermione," said Lupin with a laugh. "By now, you must know that Sirius's animal form is that of a big black dog; is his name on the register? There used to be three unregistered Animagi running around Hogwarts, but we never told anyone."

"How very fascinating," said a voice coming from behind Oleandra. "I can see the children have already done a good job disarming you. But just to be safe…"

With a small bang, Lupin and Sirius were trussed up in conjured ropes; unable to maintain their balance, they fell over like bowling pins.

"Professor Snape!" Oleandra exclaimed.

"Miss Greengrass," said Professor Snape. "Never one for rules, were you? Ever the little adventurer; eager to get back at Black, I suppose? Where are your sister and your little friend? If you're here, they must not be very far away."

"Rules are made to be taken advantage of," said Oleandra, shrugging her shoulders. "That's the Slytherin way, isn't it?"

"NO!" screamed Black hoarsely. "I WAS SO CLOSE!"

"Severus—" Lupin began, but he was immediately interrupted.

"I've told the headmaster again and again that you were helping your old friend Black into the castle, Lupin, and here's the proof. But to use your old hideout; it's smart, in a way; not even I would have considered the possibility that you'd be so sloppy as to reuse this old place."

"Severus, you're making a terrible mistake," Lupin pleaded. "You haven't heard the whole story yet— I can explain— Sirius is not here to kill Harry—"

"Two more for Azkaban tonight," said Snape with a manic gleam in his eyes. "I shall be interested to see how Dumbledore takes this... He was quite convinced you were harmless, you know, Lupin... a tame werewolf—"

"You fool," said Lupin softly. "Is a schoolboy grudge worth putting an innocent man back inside Azkaban?"

Harry's ears perked up; did this have anything to do with the reason why Snape hated him so much? Dumbledore had told him his father had saved Snape…

Meanwhile, Black was staring at Snape with eyes full of hatred. Ordinarily, if Harry had to choose, he'd side with whoever hated Snape the most, but for once in his life, he wasn't sure of who was in the right.

"Professor Snape," Hermione said timidly, "it— it wouldn't hurt to hear what they've got to say, w — would it?"

"Miss Granger, you are already facing suspension from this school," Snape spat. "You and your little friends are out-of-bounds, and have broken curfew to chase down a convicted murderer and a werewolf. You've done something positive for once in your life, so for the love of God, hold your tongue."

"And before anything else," Oleandra added, "Professor, do you have Lupin's Wolfsbane potion? Things would become complicated if he turned and went mad."

"How very true," said Professor Snape. "Which reminds me; that's how I found you all. I was heading to your office to give you your dose, Lupin, but you weren't there. Conveniently, there was a certain map on your desk. When I saw you running along this passageway on said map, I just had to catch up to you…"

Professor Snape waved his wand, conjuring a goblet full of smoking liquid and handed it to Oleandra. She knew what to do; she took the goblet and brought it up to Lupin's lips, who accepted to drink from it. Once she was sure he had drunk all of it, she tossed it aside.

"Vengeance is very sweet," Snape said, turning his attention back to Black. "How I hoped I would be the one to catch you..."

"James should have left you to die," Black snarled. "The world would have been a much better place for it."

"That's enough out of you," Professor Snape said in his low voice. "From both of you." With a wave of his wand, he conjured more ropes, gagging both Lupin and Black.

"Mmmphf!" Black tried to speak through the ropes.

"What did Black mean by that?" Harry asked Professor Snape.

"If you really must know," Professor Snape said, his upper lip curling, "Black's homicidal tendencies started at a very young age; he tried to feed me to the Werewolf here; perhaps he thought it'd be funny."

"So that's what Professor Dumbledore meant," Harry realized. "That's how my father saved your life!"

"Saving his own skin, more like," said Professor Snape coldly. "He knew he wouldn't be long for Azkaban if he let Black go through with his plan. Now, that's enough out of you— I'm taking you all back to the castle."

"Mobilicorpus!"

Lupin and Black, who were both tightly bound in magical ropes, were pulled upside-down into a vertical position in the air; feet up, and head down.

"You like?" sneered Professor Snape. "A little variation of mine; this must bring back fond memories; isn't that right, Black? You were very used to seeing me upside-down. Now, Miss Greengrass, would you kindly keep an eye on things while I step out of the room for a moment?"

And upon saying those words, Professor Snape exited the room, taking care to close the door behind him. The moment the door closed, Crookshanks leapt onto Ron's chest, paws swiping at the rat held tightly in his hands.

"Hey, get off me, you bloody thing!" shouted Ron. "OW! Scabbers, no!"

Oleandra watched as the orange cat dashed after the rat, who scurried off inside the flooring.

"He bit me!" said Ron, in a somewhat unbelieving tone. If Ron really accepted that Scabbers had been an Animagus all this time, it would have meant that he'd been sleeping with a grown man for all these years; in all honesty, he preferred not to think about it.

A few instants later, Professor Snape reopened the door, and they all started making their way back to the castle.