"Harry flung himself out from behind the bush and pulled out his wand. "EXPECTO PATRONUM!" he yelled. And out of the end of his wand burst, not a shapeless cloud of mist, but a blinding, dazzling, silver animal. He screwed up his eyes, trying to see what it was. It looked like a horse. It was galloping silently away from him, across the black surface of the lake. He saw it lower its head and charge at the swarming dementors. . . . Now it was galloping around and around the black shapes on the ground, and the dementors were falling back, scattering, retreating into the darkness. . . . They were gone. The Patronus turned. It was cantering back toward Harry across the still surface of the water. It wasn't a horse. It wasn't a unicorn, either. It was a stag. It was shining brightly as the moon above. . . it was coming back to him. . . . It stopped on the bank. Its hooves made no mark on the soft ground as it stared at Harry with its large, silver eyes. Slowly, it bowed its antlered head. And Harry realized. . . " ," he whispered. But as his trembling fingertips stretched toward the creature, it vanished."