The man's heart beats like a drum, pulsating gravely in his ears to match the frantic noise of his footsteps as he runs up the stairs. As he forces himself to climb yet another flight, the empty hallways echo with his grunting.
In those eerie moments of forced silence between a floor and the next, he can still hear that peculiar sound, a sort of low dragging of soles, somewhat metallic, somewhat subdued, never any less loud. The man only allows himself a panicky instant to look around before sprinting again, going up and up as far as his legs will carry him.
When there's no more stairs for him to climb, he dashes through the corridor looking for someone or something, for anything that can help him. He enters empty rooms filled with kibble and garbage, but as he tries to figure out the mass of broken tables and busted drawers, the scraping returns to fill his mind, leaving him no other thought. Without being able to control himself, he sprints away.
The man arrives at a room, dark and bare, and slams the door behind him before crouching in the corner. The blissful silence lasts but a second: the scraping begins again almost immediately, rising in tone and volume, slowly, surely, inexorably.
The door opens, and the cold light of the corridor fills the room, partially illuminating the man. He cowers away from the figure that enters, a decrepit old man that shuffles along dragging his feet. The old man moves with a deliberate slowness, pacing himself evenly until he's reached the corner where the man is crouching. The man notices his hands are smooth, unnaturally so, and that the skin on the man's face is pulled tight over his cheeks and nose, sagging where it shouldn't.
"What have I done?!" he yells in a shriek. He doesn't wait for an answer, nor does he need one. He knows already. "What have I done to you?!" he yells then.
The old man's eyes, two vast voids, blink once before he reaches down with his hands.
The man was found dead a few days later, still crouching in the corner. He wasn't decomposing, nor was he stiff or rigid. He was as a living man, only frigid to the touch and with his face contorted in a mask of terror.