Midnight House Number 404

Ta-ta, tap-ta. The sound of someone walking in slippers slowly came from the end of the empty corridor outside the door. Very slow. One step, one step. The sound was very soft, but it penetrated the dead silence and fell clearly on my ears. I froze instantly. I am the only one on the fourth floor. No neighbors. Who is walking? The footsteps came closer and closer, slowly walked to my door, and then... Stopped.