“Right,” he said, trying to recall as exactly as possible the wonderful, soaring sensation of his stomach.

“The incantation is this—” Lupin cleared his throat. “Expecto patronum!”

“Expecto patronum,” Harry repeated under his breath, “expecto patronum.”

“Concentrating hard on your happy memory?”

“Oh—yeah—” said Harry, quickly forcing his thoughts back to that first broom ride. “Expecto patrono—no, patronum—sorry—expecto patronum, expecto patronum—”

Something whooshed suddenly out of the end of his wand; it looked like a wisp of silvery gas.

“Did you see that?” said Harry excitedly. “Something happened!”

“Very good,” said Lupin, smiling. “Right, then—ready to try it on a dementor?”

“Yes,” Harry said, gripping his wand very tightly, and moving into the middle of the deserted classroom. He tried to keep his mind on flying, but something else kept intruding . . . Any second now, he might hear his mother again . . . but he shouldn’t think that, or he would hear her again, and he didn’t want to . . . or did he?

Lupin grasped the lid of the packing case and pulled.

A dementor rose slowly from the box, its hooded face turned toward Harry, one glistening, scabbed hand gripping its cloak. The lamps around the classroom flickered and went out. The dementor stepped from the box and started to sweep silently toward Harry, drawing a deep, rattling breath. A wave of piercing cold broke over him—

“Expecto patronum!” Harry yelled. “Expecto patronum! Expecto—”

But the classroom and the dementor were dissolving . . . Harry was falling again through thick white fog, and his mother’s voice was louder than ever, echoing inside his head—“Not Harry! Not Harry! Please—I’ll do anything—”

“Stand aside. Stand aside, girl!”

“Harry!”

Harry jerked back to life. He was lying flat on his back on the floor. The classroom lamps were alight again. He didn’t have to ask what had happened.

“Sorry,” he muttered, sitting up and feeling cold sweat trickling down behind his glasses.

“Are you all right?” said Lupin.

“Yes . . . ” Harry pulled himself up on one of the desks and leaned against it.

“Here—” Lupin handed him a Chocolate Frog. “Eat this before we try again. I didn’t expect you to do it your first time; in fact, I would have been astounded if you had.”

“It’s getting worse,” Harry muttered, biting off the Frog’s head. “I could hear her louder that time—and him—Voldemort—”

Lupin looked paler than usual.

“Harry, if you don’t want to continue, I will more than understand—”

“I do!” said Harry fiercely, stuffing the rest of the Chocolate Frog into his mouth. “I’ve got to! What if the dementors turn up at our match against Ravenclaw? I can’t afford to fall off again. If we lose this game we’ve lost the Quidditch Cup!”

“All right then . . . ,” said Lupin. “You might want to select another memory, a happy memory, I mean, to concentrate on . . . That one doesn’t seem to have been strong enough . . . ”