Her technician, Marco, plugged his laptop into the serial port. “It’s not hardware,” he muttered. “The firmware is corrupted. It’s like the brain forgot how to write memories.”

The monitor flickered. Dates reappeared. And the hooded man in the footage took another step.

Then Lena remembered the old security guard, Mr. Elian. He kept a “digital apocalypse kit”—a shoebox of USB drives, each labeled with sharpie.