My roommate kept saying someone was coming into our flat at night. I thought she was losing it until I found what was on my pillow. I had lived with my roommate, Piper, for six months. We split the rent, $950 each, and the groceries. She was quiet and neat, and she worked early shifts at a bakery. We never fought. One morning she was standing at the front door, staring at it. “Did you unlock this last night?” “No.” “It was unlocked when I woke up.” “You probably forgot to lock it.” “I never forget.” I shrugged and made coffee. Two nights later, she knocked on my door at 3 a.m. “Zuri, someone’s in the hallway.” “Piper, it’s the pipes.” “They stopped outside my room.” I walked her back to bed and checked every corner. Nothing. The next week, she said her cereal kept moving. “It’s on the wrong shelf.” “You moved it.” “I didn’t.” I stopped arguing with her about it. Then one morning, I woke up and found a small paper boat on my pillow. It was folded from old newspaper, yellowed at the edges. I turned it over in my hands. “Is this a joke?” “What?” I held it up. Her face went pale. “Where did you find that?” “On my pillow.” “Zuri.” “What?” “Don’t throw it away.” “Why?” “Just don’t.” I put it on my shelf. Three days later, there was another one. Then a third. Each one was folded exactly the same way. I stopped laughing at her after that.