Snape and Lily's daughter

Attack on the teacher

"What sort of animal —?" Harry began, but Hermione cut him off. "That was still really dangerous! Running around in the dark with a werewolf! What if you'd given the others the slip, and bitten somebody?"

"A thought that still haunts me," Lupin said heavily. "And there were near misses, many of them. We laughed about them afterwards. We were young, thoughtless — carried away with our own cleverness. All this year, I have been battling with myself, wondering whether I should tell Dumbledore that Sirius was an Animagus. But I didn't do it. Why? Because I was too cowardly. It would have meant admitting that I'd betrayed his trust while I was at school, admitting that I'd led others along with me... so, in a way, Snape's been right about me all along."

He said the last part while looking at Grace.

"Snape?" Black said harshly. "What's Snape got to do with it?"

"He's here, Sirius," Lupin said. "He's teaching here as well. He fought very hard against my appointment to the Defense Against the Dark Arts job. He has been telling Dumbledore all year that I am not to be trusted. He has his reasons... you see, Sirius here played a trick on him which nearly killed him, a trick which involved me —"

"It served him right," he sneered. "Sneaking around, trying to find out what we were up to... hoping he could get us expelled..."

Grace had an agry look on her face.

"Severus was very interested in where I went every month." Lupin told, Grace, Harry, Ron, and Hermione. "We were in the same year, you know, and we — er — didn't like each other very much. He especially disliked James. Jealous, I think, of James's talent on the Quidditch field... Sirius thought it would be — er — amusing, to tell Snape all he had to do was prod the knot on the tree trunk with a long stick, and he'd be able to get in after me. Well, of course, Snape tried it — if he'd got as far as this house, he'd have met a fully grown werewolf... but your father, who'd heard what Sirius had done, went after Snape and pulled him back, at great risk to his life... Snape glimpsed me, though, at the end of the tunnel. He was forbidden by Dumbledore to tell anybody, but from that time on he knew what I was..."

"So that's why my father doesn't like you," Grace spoke. "because he thought you were in on the joke?" when she mentioned her father, Sirius immediately glared at her.

"That's right, dear," a cold voice said, coming from behind Lupin.

Severus Snape was pulling off the Invisibility Cloak, his wand pointing directly at Lupin.

Hermione screamed. Harry leapt to his feet.

"I found this at the base of the Whomping Willow," Snape said. "Very useful, Potter, I thank you..."

Snape was slightly breathless, but his face was full of suppressed triumph. "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 Snape interrupted him.

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

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

"Two more for Azkaban tonight. 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," Lupin said softly. "Is a schoolboy grudge worth putting an innocent man back inside Azkaban?"

Thin, snakelike cords burst from the end of Snape's wand and twisted themselves around Lupin's mouth, wrists, and ankles; he overbalanced and fell to the floor, unable to move. Black started toward Snape, but Snape pointed his wand straight between Black's eyes.

"Give me a reason," Snape said. "Give me a reason to do it, and I swear I will."

"Dad, no!" Grace said, but Snape was too focused on Black.

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

"Miss Granger, you are already facing suspension from this school," Snape spat. "You, Potter, Weasley, and Snape are out-of-bounds, in the company of a convicted murderer and a werewolf. For once in your life, hold your tongue."

Then he turned to Black. "Vengeance is very sweet. How I hoped I would be the one to catch you..." Snape whispered.

"You — you've got to hear me out," Sirius croaked. "The rat — look at the rat —"

"Come on, all of you," Snape said, pointing at the door.

Without thinking, Harry raised his wand. "Expelliarmus!"

Snape was lifted off his feet and slammed into the wall, then slid down it to the floor, a trickle of blood oozing from under his hair.

Grace went to check on her father, and noticed that Hermione and Ron also had used the same spell on her father.

"WHAT HAVE YOU DONE!" Grace screamed.