I check the date: the year after Felix was born. Something niggles. I’d assumed that the course they did had been more recent, more local to us, for some reason. But the four-day residential course was nearby, here, in Dartmoor.

I do the math as I think back to the photos I recently viewed. Greg had been at the barbecue to celebrate Nina’s birthday, a year before he moved to the area. I access the copies of Nina’s album on my phone. I scroll, then enlarge Greg’s face. I don’t think I’m imagining it: he’s staring in Nina’s direction with what I can only perceive as admiration or longing. It’s unnerving.

My appetite disappears as I sit down opposite Stuart at dinner. I go through the motions of conversation with the children, but it’s hard. I can’t stop thinking about Greg and Nina, because no matter how I try to look at it, I can’t shake off the feeling that Nina was Greg’s mystery love. If that’s true, then I’ve missed even more than I realized.

Camilla’s arrival the following lunchtime brings further unsettlement. I’d forgotten that it somehow takes a few days to get into a holiday rhythm, more so, I now realize, when you’re a family. A late guest shakes up the routine. Her arrival makes me doubt the wisdom of my plan. I’m unsure how to be with her: is she a genuine guest, a fellow holiday companion, an unlikely friend or an enemy I need to be wary of? Our relationship is more blurred than ever.

We opt for a waterfall visit. I’ll walk as far as feels comfortable, then chill in the café nearby. I may even suggest that Camilla accompany me back down. Perhaps I can get her to talk candidly then, rather than force it out of her somehow.

Lush green foliage borders the lakes. We select one of the easier walks, supposedly for me, but really it’s for Emily, and meander through fern gardens. It’s the coolest I’ve felt all week, and caught up in nature’s beauty, it briefly dulls my ever-gnawing need to push Camilla for the truth. But every time I catch sight of Louise’s smile or hear her laugh, it reminds me that I owe this to Charlie.

Random dark thoughts ping into my mind. Like, how easy it would be to push Camilla over and onto the rocks. Bye bye, Camilla. I even conduct the imaginary aftermath conversation in my head: It was an accident, she slipped right in front of me. So shocking. So terrible. I’d adopt Louise as well as Felix and Em.

I stop myself. I’m glad no one can read my thoughts.

While Stuart and the children are packing up in the morning (he is going to drop Louise at her grandparents’ for the weekend), my resolve is tested when Louise asks if she can stay with us instead. Everyone looks at me. Camilla doesn’t want to admit to Louise that she’s invited Greg to join us. “We’ll go out, leave you in peace,” Camilla had said. “Greg wants to show me his home area, so sweet, don’t you think?”