For a full minute, she sat in the dark, heart pounding. Then, slowly, she opened the laptop again.

The screen went black. When it flickered back on, she was looking at a live feed of her own building's lobby. And someone was walking toward her front door.

Mia frowned. Probably just a troll. She refreshed the page. The comment was gone. In its place, a new one had appeared from the same user: "Check your email."

Her finger hovered over the keyboard. Outside, a siren wailed in the distance. Somewhere in the city, someone else was probably clicking the same link, watching the same impossible thing.