Pulling out my phone, I type in the postcode and wait for the screen to load. It brings up a Google map, a red pin indicating the location of the postcode on the map. I zoom in, noting down the road name and the location. Norfolk. Exactly where Fran said Polly was staying. So, Fran must have always intended to go and stay with Polly, and by hiding this under the mattress, she didn’t want Dominic to know about it.

I don’t know what to think – was Fran planning on leaving Dominic, even though she seemed to be terrified that he would leave her? Or did this come about after Laurel’s disappearance? Although I now think I have found where Fran is staying, it still doesn’t tell me whether Pamela is right when she said Fran isn’t so innocent. And I still can’t shake off that feeling that something isn’t quite right – and that Fran hasn’t been entirely truthful.

I leave Fran and Dominic’s room and head back down the narrow flight of stairs to the landing, bypassing my own bedroom door and heading for Laurel’s. As I push the door open, I think I catch a faint whiff of her baby scent, and my stomach clenches with longing. Her dressing gown, pink and fluffy, hangs on the back of the door, and Bom, her stuffed tiger, sits next to her nightlight, almost as though she’s about to come running in from her bath, ready to go to bed.

Fighting back hot tears, I blink rapidly, and get back to the task in hand. I still have that itchy feeling at the back of my brain that tells me somebody said something, or I saw something, something that wasn’t quite right and that I can’t put my finger on. Something that could tell me once and for all whether I am barking up the wrong tree. Whether Dominic is innocent or guilty.

Fumbling through Laurel’s toy box, I try hard not to get distracted by the items I find, memories of pretend tea parties, building Lego houses, dressing dolls in radical outfits assaulting me from all sides, and making me only all too aware of my grief. There is nothing, so I move to the chest of drawers, the one Dominic brought home from Ikea and that Fran then decided to paint in Farrow and Ball – the one that I once caught Laurel about to stick stickers all over and had to rescue before Fran noticed. I dig in to the top drawer, scrabbling through vests, tiny pairs of pants and socks, before I see it, and I freeze, the hot, acid burn of bile scorching the back of my throat.

This is it – this is what I was looking for, the thing that I couldn’t quite put my finger on. A tiny lemon yellow sock, with a white lace frill around the ankle.