The letter arrived without a return address, but she knew exactly who had sent it. It was part of the experiment. It had to be. Dr. Elin Voss adjusted the camera angle slightly, making sure both the envelope and her face were visible to the live feed. “Subject received anomalous physical correspondence at 21:43,” she said calmly. “No postal markings. No identifiable delivery method.” Her voice sounded steadier than she felt. The lab was sealed. It had been for weeks. No external contact. No variables. That was the point. She opened the envelope. Inside: We see you. Her stomach dropped. She glanced instinctively at the cameras. “Note: message appears responsive,” she said, forcing clinical detachment. “Potential feedback loop between observer and subject.” The overhead lights flickered. The monitors behind her glitched briefly, static crawling across the screens. Her breath caught. “System instability detected,” she murmured. The letter shifted in her hand. Not instability. A pause. Then— Presence. Elin swallowed. “This is controlled,” she said, more to herself than the recording. “Everything here is controlled.” One of the monitors turned on. No input. No command. Just— Video. Her lab. From a different angle. Behind her. She turned slowly. The camera in the corner was still fixed in place. Unmoving. The screen flickered again. Now the angle was closer. Lower. Watching her. The letter grew warm. You opened the channel. “I closed it,” she said. “Days ago.” The lights dimmed. The monitors multiplied. Every screen now showed her. Different angles. Different moments. Some delayed. Some… ahead. On one screen, she was standing still. On another, she was already turning. On one— She wasn’t there at all. The letter slipped from her hand. She picked it up with shaking fingers. We are still reading. The room felt smaller. Denser. Occupied. She looked into the camera. Into the lens. Into whatever might be watching from the other side. “I’m ending the session,” she said. But she didn’t move to shut anything down. Didn’t cut the feed. Didn’t power off the lights. She left the light on, just in case someone - or something - was still reading.