We're four. My wife, the two kids, me.

I count them every night. It's a habit from when the youngest was small and used to sleepwalk. You learn to do a sweep before bed. Two small shapes, one big one, the dog. Everyone breathing.

Four people, one dog. I count them on my fingers in the dark like a man patting his pockets for keys.

Tuesday I counted five.

Not a shape. Not a sound. The number was just five, the way you know a word is spelled wrong before you can say why. I counted again. Four. I went to sleep.

Wednesday, five.

I checked the rooms. The kids were in their beds. My wife was in ours. The dog lifted his head, looked at the hallway, put it back down. I stood in the kitchen at 3 a.m. and counted the house like a teller counts a drawer, and the house came back five, and there was no fifth.

I haven't told her. What would I say. There's an extra one of us and I can't find them.

Tonight I did the sweep early. Kids, wife, dog. Four. I felt the relief go through me like warm water.

Then I remembered I was counting.

Then I remembered I'm one of the five.

I'm sitting on the edge of the bed now. My wife is asleep. The kids are asleep. The dog is watching the hallway again.

I'm trying to work out, very quietly, which one of us doesn't belong.