The cursor blinked on the vintage Dell monitor like a patient heartbeat. For three hours, Leo had been staring at the Device Manager window, its yellow exclamation marks glaring back at him like angry little sentinels.

“Unknown Device. Unknown Device. Ethernet Controller.”

The screen went black. Then, slowly, the Windows 10 login sound crackled through his speakers—but it was wrong. It was slowed down, distorted, and underneath it, a faint, rhythmic tapping. Morse code.