On screen, Mr. Aris reached out a hand, his fingers stretching toward the lens until they seemed to press against the glass of my monitor.

I reached for the mouse to close the window, but the cursor wouldn't move. The speakers began to hum with a low-frequency vibration that made my teeth ache.

Mr. Aris stopped writing. He didn't turn around. "Do you have the answer, Leo?"

Suddenly, the video glitched. The colors inverted, turning the sunset purple and the shadows neon green. When the image stabilized, Mr. Aris was standing directly in front of the camera. His face filled the entire screen. The glare was gone from his glasses, revealing empty, black sockets. "You're late for class," he said.

The boy didn't move. The camera zoomed in on the back of his head. I noticed a small flickering at the edge of the screen—a digital artifact that looked like a barcode.

The file was buried in a folder named RECOVERY_2012 on an old external hard drive I found at a yard sale. Amidst blurry vacation photos and dead links was a single video file: .