The Hidden Resident Next Door

I'm a fresh graduate who rented a run-down resettlement building to save money. The landlord strongly recommended the top floor at an absurdly low price, with one rule: don't mind the neighbor, don't knock on the neighbor's door, and don't look through the peephole at night. After moving in, strange things kept happening. The neighbor's door was always shut tight, and the property records said: vacant for three years, no one lives there. But every night, I could hear dragging sounds, whispers, and pacing. The peephole was always blocked with black cloth, there were footprints that didn't belong to me at my door, and at night, a dark figure would stand still at the end of the hallway. I thought it was a homeless person or a pervert spying. It wasn't until I reviewed the old hallway surveillance, pried open the door crack for evidence, and searched floor by floor that I discovered the chilling truth: the neighbor wasn't hiding a stranger at all. — Description from novelcodex.org