Hermione screamed. Black leapt to his feet. Harry felt as though he’d received a huge electric shock.
“I found this at the base of the Whomping Willow,” said Snape, throwing the cloak aside, careful to keep this wand pointing directly at Lupin’s chest. “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?” he said, his eyes glittering. “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 overrode 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,” said Lupin urgently. “You haven’t heard everything—I can explain—Sirius is not here to kill Harry—”
“Two more for Azkaban tonight,” said Snape, his eyes now gleaming fanatically. “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?”
BANG! 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. With a roar of rage, Black started toward Snape, but Snape pointed his wand straight between Black’s eyes.
“Give me a reason,” he whispered. “Give me a reason to do it, and I swear I will.”
Black stopped dead. It would have been impossible to say which face showed more hatred.
Harry stood there, paralyzed, not knowing what to do or whom to believe. He glanced around at Ron and Hermione. Ron looked just as confused as he did, still fighting to keep hold on the struggling Scabbers. Hermione, however, took an uncertain step toward Snape and said, in a very breathless voice, “Professor Snape—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, Potter, and Weasley are out of bounds, in the company of a convicted murderer and a werewolf. For once in your life, hold your tongue.”
“But if—if there was a mistake—”
“KEEP QUIET, YOU STUPID GIRL!” Snape shouted, looking suddenly quite deranged. “DON’T TALK ABOUT WHAT YOU DON’T UNDERSTAND!”