Then the sound started. A low, wet thump from her subwoofer. Thump. Thump. Thump. It wasn't a system beep. It was rhythmic. Organic.

She stood up, knocking her chair over. The thumping grew louder. Her phone buzzed on the desk. A text from an unknown number: "The memory could not be read. But it can be written."

She held down Ctrl+Alt+Del. Nothing. The error windows began multiplying like rabbits, stacking in a growing column from the bottom of her screen to the top. Her fan, usually a quiet whisper, roared to life like a jet engine.

The thumping stopped. The fans stopped. The lights in her apartment went out.

Lena blinked. "What?"

She never pressed a thing. But the error clicked itself anyway.

The instruction at 0x745F3A1C referenced memory at 0x00000000. The memory could not be "read".

Her monitor flickered. The error text began to change. The hexadecimal addresses didn't look random anymore. They looked like coordinates. Latitude. Longitude. Her latitude. Her apartment building.

Lena ran for the door. She didn't make it. The last error window bloomed across all three of her monitors at once, huge and red:

She clicked.