“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.