Elias leaned in, his nose inches from the monitor. In that second room, he saw the back of a man sitting at a desk, illuminated by the blue glow of a computer screen.

On the screen within the screen, Elias saw a tiny version of himself leaning toward the monitor. A cold realization washed over him: the file wasn't a recording of the past. The "thumping" sound wasn't static—it was the sound of someone knocking on the floorboards directly beneath his feet.

He clicked it. The player opened to a grainy, low-bitrate shot of a kitchen. It was unremarkable—a bowl of fruit on the counter, a ticking clock, a half-empty glass of milk. But there was no sound, only a low, rhythmic thumping that seemed to vibrate the speakers without making a noise.

The man in the video paused. He slowly turned his head toward the "camera."

Elias froze. The man in the video wasn't just a recording; he was wearing the same headset Elias was wearing. He was sitting in the same chair.