They waited, watching the moving clouds reflected in the lake, while the bush next to them whispered in the breeze. Buckbeak, bored, was ferreting for worms again.
“D’ you reckon he’s up there yet?” said Harry, checking his watch. He looked up at the castle and began counting the windows to the right of the West Tower.
“Look!” Hermione whispered. “Who’s that? Someone’s coming back out of the castle!”
Harry stared through the darkness. The man was hurrying across the grounds, toward one of the entrances. Something shiny glinted in his belt.
“Macnair!” said Harry. “The executioner! He’s gone to get the Dementors! This is it, Hermione—”
Hermione put her hands on Buckbeak’s back and Harry gave her a leg up. Then he placed his foot on one of the lower branches of the bush and climbed up in front of her. He pulled Buckbeak’s rope back over his neck and tied it to the other side of his collar like reins.
“Ready?” he whispered to Hermione. “You’d better hold on to me—”
He nudged Buckbeak’s sides with his heels.
Buckbeak soared straight into the dark air. Harry gripped his flanks with his knees, feeling the great wings rising powerfully beneath them. Hermione was holding Harry very tight around the waist; he could hear her muttering, “Oh, no—I don’t like this—oh, I really don’t like this—”
Harry urged Buckbeak forward. They were gliding quietly toward the upper floors of the castle… Harry pulled hard on the left hand side of the rope, and Buckbeak turned. Harry was trying to count the windows flashing past—
“Whoa!” he said, pulling backward as hard as he could.
Buckbeak slowed down and they found themselves at a stop, unless you counted the fact that they kept rising up and down several feet as the hippogriff beat his wings to remain airborne.
“He’s there!” Harry said, spotting Sirius as they rose up beside the window. He reached out, and as Buckbeak’s wings fell, was able to tap sharply on the glass.
Black looked up. Harry saw his jaw drop. He leapt from his chair, hurried to the window and tried to open it, but it was locked.
“Stand back!” Hermione called to him, and she took out her wand, still gripping the back of Harry’s robes with her left hand.
“Alohomora!”
The window sprang open.
“How—how—?” said Black weakly, staring at the hippogriff.
“Get on—there’s not much time,” said Harry, gripping Buckbeak firmly on either side of his sleek neck to hold him steady. “You’ve got to get out of here—the Dementors are coming—Macnair’s gone to get them.”
Black placed a hand on either side of the window frame and heaved his head and shoulders out of it. It was very lucky he was so thin. In seconds, he had managed to fling one leg over Buckbeak’s back and pull himself onto the hippogriff behind Hermione.
“Okay, Buckbeak, up!” said Harry, shaking the rope. “Up to the tower—come on.”
The hippogriff gave one sweep of its mighty wings and they were soaring upward again, high as the top of the West Tower. Buckbeak landed with a clatter on the battlements, and Harry and Hermione slid off him at once.
“Sirius, you’d better go, quick,” Harry panted. “They’ll reach Flitwick’s office any moment, they’ll find out you’re gone.”