Harry Potter and the Half-Blood Prince

And Harry realized, with a shock so huge it seemed to root him to the spot, that Malfoy was crying—actually crying—tears streaming down his pale face into the grimy basin. Malfoy gasped and gulped and then, with a great shudder, looked up into flu-cracked mirror and saw Harry staring at him over his shoulder.

Malfoy wheeled around, drawing his wand. Instinctively, Harry pulled out his own. Malfoy’s hex missed Harry by inches, shattering the lamp on the wall beside him; Harry threw himself sideways, thought Levicorpus! and flicked his wand, but Malfoy blocked the jinx and raised his wand for another—

“No! No! Stop it!” squealed Moaning Myrtle, her voice echoing loudly around the tiled room. “Stop! STOP!”

There was a loud bang and the bin behind Harry exploded; Harry attempted a Leg-Locker Curse that backfired off the wall behind Malfoy’s ear and smashed the cistern beneath Moaning Myrtle, who screamed loudly; water poured everywhere and Harry slipped as Malfoy, his face contorted, cried, “Cruci—”

“SECTUMSEMPRA!” bellowed Harry from the floor, waving his wand wildly.

Blood spurted from Malfoy’s face and chest as though he had been slashed with an invisible sword. He staggered backward and collapsed onto the waterlogged floor with a great splash, his wand falling from his limp right hand.

“No—” gasped Harry.

Slipping and staggering, Harry got to his feet and plunged toward Malfoy, whose face was now shining scarlet, his white hands scrabbling at his blood-soaked chest.

“No—I didn’t—”

Harry did not know what he was saying; he fell to his knees beside Malfoy, who was shaking uncontrollably in a pool of his own blood. Moaning Myrtle let out a deafening scream:

“MURDER! MURDER IN THE BATHROOM! MURDER!”

The door banged open behind Harry and he looked up, terrified: Snape had burst into the room, his face livid. Pushing Harry roughly aside, he knelt over Malfoy, drew his wand, and traced it over the deep wounds Harry’s curse had made, muttering an incantation that sounded almost like song. The flow of blood seemed to ease; Snape wiped the residue from Malfoy’s face and repeated his spell. Now the wounds seemed to be knitting.

Harry was still watching, horrified by what he had done, barely aware that he too was soaked in blood and water. Moaning Myrtle was still sobbing and wailing overhead. When Snape had performed his countercurse for the third time, he half-lifted Malfoy into a standing position.

“You need the hospital wing. There may be a certain amount of scarring, but if you take dittany immediately we might avoid even that… Come…”

He supported Malfoy across the bathroom, turning at the door to say in a voice of cold fury, “And you, Potter… You wait here for me.”

It did not occur to Harry for a second to disobey. He stood up slowly, shaking, and looked down at the wet floor. There were bloodstains floating like crimson flowers across its surface. He could not even find it in himself to tell Moaning Myrtle to be quiet, as she continued to wail and sob with increasingly evident enjoyment.

Snape returned ten minutes later. He stepped into the bathroom and closed the door behind him.

“Go,” he said to Myrtle, and she swooped back into her toilet at once, leaving a ringing silence behind her.

“I didn’t mean it to happen,” said Harry at once. His voice echoed in the cold, watery space. “I didn’t know what that spell did.”

But Snape ignored this. “Apparently I underestimated you, Potter,” he said quietly. “Who would have thought you knew such Dark Magic? Who taught you that spell?”

“I—read about it somewhere.”

“Where?”

“It was—a library book,” Harry invented wildly. “I can’t remember what it was call—”

“Liar,” said Snape. Harry’s throat went dry. He knew what Snape was going to do and he had never been able to prevent it…

The bathroom seemed to shimmer before his eyes; he struggled to block out all thought, but try as he might, the Half-Blood Prince’s copy of Advanced Potion-Making swam hazily to the forefront of his mind.

And then he was staring at Snape again, in the midst of this wrecked, soaked bathroom. He stared into Snape’s black eyes, hoping against hope that Snape had not seen what he feared, but—

“Bring me your schoolbag,” said Snape softly, “and all of your schoolbooks. All of them. Bring them to me here. Now!”

There was no point arguing. Harry turned at once and splashed out of the bathroom. Once in the corridor, he broke into a run toward Gryffindor Tower. Most people were walking the other way; they gaped at him, drenched in water and blood, but he answered none of the questions fired at him as he ran past.