When I go upstairs to bed at nearly midnight I see a light still on in Sam’s room; his door isn’t all the way closed.

“Sam?” I tap, and hear him clearing his throat.

“Yeah?” he says.

I crane my head around the door. He’s on his phone; I don’t know whether I should say something about it.

“It’s bedtime, Sam,” I say. “In fact it was bedtime an hour ago.”

He looks at me.

“I can’t sleep.”

I can believe that.

“Well… can I get you something?” I say. “A… glass of milk, or something?”

I don’t know if ten-year-old boys drink milk anymore, and I suspect I sound a bit Little House on the Prairie, much too wholesome and woefully out of date. When I was a teenager I always imagined myself being a young mom, a young cool mom. One who didn’t use all the wrong slang and get constantly confused about what was in or out of fashion. I figured I’d just know these things.

I pictured myself getting married soon after college, having a big family—nothing too rushed, we’d have time because we married young. Four, I used to think. Four would be nice and comfortable and noisy. I pictured sons, their forever dirty boy-hands, the raucous overlapping voices; the ketchup stains and clumsiness and unrepentant curiosity.

If that fantasy timeline had worked out, Sam would be the age of that eldest son now. I look at him, bleary-eyed, sleepy or just faking it to get me out of here. He turns on his side, away from me.

“I’m not thirsty,” he says.

”Okay.” I contain a sigh. “But please turn out the light, all right?”

The night is cold and in the main bedroom I pull an extra blanket onto the bed. I hope Sam’s warm enough next door; I left some spare blankets on a chair for him in case. I settle into bed and turn onto my side. Out the window, the moon is a tiny crescent.

The lights are off but I don’t think Oliver’s asleep yet. I say his name and he grunts.

“Did you really mean it earlier, about Abigail having an affair?”

I know they have actual apps now just for married people who are looking for affairs, people who get a thrill out of cheating on their spouses.

“Probably,” Oliver mutters. “I don’t know, Gill.”

I roll over. “Is that what you would think if I disappeared—that I was having an affair?”

He sighs.

“You’re not going to disappear, Gillian.”

I blink into the darkness. It’s true, of course. Is it odd that I feel somehow slighted? As if I’m not…interesting enough to disappear.

I roll back over on my side and stare at the tiny fingernail of moon.