With a stab of horror, Harry saw Moody point at the Marauder’s Map, still lying on the staircase six steps below him. As Snape and Filch both turned to look at it, Harry threw caution to the winds; he raised his arms under the cloak and waved furiously at Moody to attract his attention, mouthing “It’s mine! Mine!”

Snape had reached out for it, a horrible expression of dawning comprehension on his face—

“Accio Parchment!”

The map flew up into the air, slipped through Snape’s outstretched fingers, and soared down the stairs into Moody’s hand.

“My mistake,” Moody said calmly. “It’s mine—must’ve dropped it earlier—”

But Snape’s black eyes were darting from the egg in Filch’s arms to the map in Moody’s hand, and Harry could tell he was putting two and two together, as only Snape could . . .

“Potter,” he said quietly.

“What’s that?” said Moody calmly, folding up the map and pocketing it.

“Potter!” Snape snarled, and he actually turned his head and stared right at the place where Harry was, as though he could suddenly see him. “That egg is Potter’s egg. That piece of parchment belongs to Potter. I have seen it before, I recognize it! Potter is here! Potter, in his Invisibility Cloak!”

Snape stretched out his hands like a blind man and began to move up the stairs; Harry could have sworn his over-large nostrils were dilating, trying to sniff Harry out—trapped, Harry leaned backward, trying to avoid Snape’s fingertips, but any moment now—

“There’s nothing there, Snape!” barked Moody, “but I’ll be happy to tell the headmaster how quickly your mind jumped to Harry Potter!”

“Meaning what?” Snape turned again to look at Moody, his hands still outstretched, inches from Harry’s chest.

“Meaning that Dumbledore’s very interested to know who’s got it in for that boy!” said Moody, limping nearer still to the foot of the stairs. “And so am I, Snape . . . very interested . . . ” The torchlight flickered across his mangled face, so that the scars, and the chunk missing from his nose, looked deeper and darker than ever.

Snape was looking down at Moody, and Harry couldn’t see the expression on his face. For a moment, nobody moved or said anything. Then Snape slowly lowered his hands.

“I merely thought,” said Snape, in a voice of forced calm, “that if Potter was wandering around after hours again . . . it’s an unfortunate habit of his . . . he should be stopped. For—for his own safety.”

“Ah, I see,” said Moody softly. “Got Potter’s best interests at heart, have you?”

There was a pause. Snape and Moody were still staring at each other. Mrs. Norris gave a loud meow, still peering around Filch’s legs, looking for the source of Harry’s bubble-bath smell.

“I think I will go back to bed,” Snape said curtly.