We had installed a small security camera in the upstairs hallway years ago, back when Roger was a baby and we worried about him on the stairs, and it saved its footage to a cloud account we’d both long forgotten.

Gideon, it turned out, had remembered it just enough to delete what he thought was the record off the device itself — but he did not understand, the way my brother understood, that deleting the local copy does not touch the cloud.

Two hours later my brother sent me a file.

And on it, time-stamped at eleven o’clock the night before, was my husband, leading our son by the hand down the hallway, crouching to say something to him, pointing him toward the kitchen — and then walking back and opening the guest room door, and closing it behind himself and my sister.

It was all there.