Late that night, Hogwarts fell asleep as it always did. Most of the Dementors that usually drifted around it like scraps of cloth were gone, and it looked as though the rest would leave before long.
Gryffindor Tower was silent. Even the young wizards who liked sneaking out at night seemed to be sleeping soundly.
Ron Weasley turned uneasily in his sleep. His pet rat, Scabbers, lay curled beside his pillow, sleeping just as fitfully and twitching now and then.
The dormitory door opened a crack without a sound, letting in a cold draft.
A tall, gaunt figure in ragged clothes slipped inside like a ghost. Tangled, greasy black hair nearly hid his face, but his sunken eyes gleamed with feverish urgency in the dark. His gaze swept the room and fixed at once on the dusty gray rat on Ron's bed.
Sirius suppressed the excitement and hatred churning in his chest and crept toward Ron's bed. His fingers trembled slightly, not from fear, but from years of pent-up emotion and the thrill of closing in on his target.
But just as his fingertips were about to touch the sleeping rat—
"Who's there?!"
Harry Potter jolted awake. He had slept badly all night, as though something had been disturbing his dreams. A cold draft brushed his neck, and he sat up groggily, catching sight of the dark figure beside the bed.
Sirius froze. He turned toward Harry.
In the faint moonlight filtering through a gap in the curtains, Harry saw a haggard, wild face marked by what looked like bottomless grief, and eyes fixed unblinkingly on him.
Time seemed to stand still. But the startled rat reacted, darting under the bed and vanishing into the shadows.
Harry raised his wand. "Expelliarmus!"
Sirius spun away like a streak of black lightning,