The yelping stopped abruptly. As they reached the lakeshore, they saw why—Sirius had turned back into a man. He was crouched on all fours, his hands over his head.
“Nooo,” he moaned. “Nooo… please…”
And then Harry saw them. Dementors, at least a hundred of them, gliding in a black mass around the lake toward them. He spun around, the familiar, icy cold penetrating his insides, fog starting to obscure his vision; more were appearing out of the darkness on every side; they were encircling them…
“Hermione, think of something happy!” Harry yelled, raising his wand, blinking furiously to try and clear his vision, shaking his head to rid it of the faint screaming that had started inside it—I’m going to live with my godfather. I’m leaving the Dursleys.
He forced himself to think of Black, and only Black, and began to chant: “Expecto patronum! Expecto patronum!”
Black gave a shudder, rolled over, and lay motionless on the ground, pale as death.
He’ll be all right. I’m going to go and live with him.
“Expecto patronum! Hermione, help me! Expecto patronum!”
“Expecto—” Hermione whispered, “expecto—expecto—”
But she couldn’t do it. The Dementors were closing in, barely ten feet from them. They formed a solid wall around Harry and Hermione, and were getting closer…
“EXPECTO PATRONUM!” Harry yelled, trying to blot the screaming from his ears. “EXPECTO PATRONUM!”
A thin wisp of silver escaped his wand and hovered like mist before him. At the same moment, Harry felt Hermione collapse next to him. He was alone… completely alone…
“Expecto—expecto patronum—”
Harry felt his knees hit the cold grass. Fog was clouding his eyes. With a huge effort, he fought to remember—Sirius was innocent—innocent—We’ll be okay—I’m going to live with him—
“Expecto patronum!” he gasped.
By the feeble light of his formless Patronus, he saw a Dementor halt, very close to him. It couldn’t walk through the cloud of silver mist Harry had conjured. A dead, slimy hand slid out from under the cloak. It made a gesture as though to sweep the Patronus aside.
“No—no—” Harry gasped. “He’s innocent… expecto—expecto patronum—”
He could feet them watching him, hear their rattling breath like an evil wind around him. The nearest Dementor seemed to be considering him. Then it raised both its rotting hands—and lowered its hood.
Where there should have been eyes, there was only thin, gray scabbed skin, stretched blankly over empty sockets. But there was a mouth… a gaping, shapeless hole, sucking the air with the sound of a death rattle.