I accepted it the first time. The second time, my logistical brain started to itch.

The router was brand new. The plug was hidden behind a heavy dresser.

By the third time, I noticed something else: when I got home, Brooke was more withdrawn each day, her eyes red-rimmed, her hands trembling. Whenever Lorraine entered the room, Brooke flinched.

Something is wrong, a voice in my head said. The math isn’t adding up.

I stopped guessing. I decided to gather data.

I bought a second camera — a tiny battery-operated device disguised as a digital clock, completely independent of the house Wi-Fi.