When I moved into my new apartment, the landlord gave me one strange warning. Don't open apartment 4B I laughed because I thought he was joking. He wasn't. He told me the apartment had been empty for almost ten years. The previous tenant had disappeared without paying rent, and nobody had been allowed inside since. I asked why they didn't simply open it. The landlord said Because every person who tried eventually left the building I assumed it was an old man's superstition. For the first few weeks, nothing happened. Then I started hearing footsteps above my bedroom. Every night. Always at 2:17 AM. I lived on the top floor. There was no apartment above me. I ignored it until one night I heard someone knocking on my ceiling. Three slow knocks. Then three more. I contacted the landlord. He told me not to investigate. That only made me more curious. The next morning I found something outside my door. A small brass key. Attached to it was a piece of paper. It said 4B I waited until the landlord left the building. Then I walked upstairs. The door to 4B was covered in dust. I put the key inside. It opened. The apartment looked exactly like someone had just left. A cup of coffee sat on the table. A newspaper was lying beside it. The date on the newspaper was ten years old. Then I noticed photographs covering the wall. Every photograph showed people who had lived in the building. There were dozens of them. But the final photograph made my blood run cold. It was a picture of me. Standing outside the building. Taken three days before I moved in. I heard footsteps behind me. I turned around. The landlord was standing in the doorway. He looked terrified. I asked him who had taken the photograph. He didn't answer. Instead, he looked at the wall and whispered You weren't supposed to find that room I asked what he meant. He closed the door behind him. Then he said The person who lived here before you didn't disappear He has been living inside this building the entire time. I asked where. The landlord pointed toward the floor beneath us. And said He's underneath your apartment.