Kat’s itching to get inside now. She wants to reach out to the thin ceramic table lined up against the stairs and pick up each photo frame in turn, scrutinise the pictures of Beth’s family. From this angle she can see only the far end of the table, and just make out the faces of two little girls in matching rainbow-striped dresses. Another picture is a family shot taken in one of those studios, a soft white background with the four of them smiling in loose linen clothing. She can’t see the other side of the table. She wonders if there are pictures of Beth’s mum and dad, and if they’re beautiful like her; they were always a mystery, even back then.

One of the girls from the photo tumbles out of the kitchen, being dragged down the hallway by Luna, who’s attached via the lead.

‘Careful, Martha,’ Beth says, a little tut escaping. ‘Kat’s going to think we have no control over our dog.’

That’s her cue to speak, Kat realises with a start. ‘Not at all,’ she says. ‘Luna’s still a puppy really – she’s bound to get excited when there’s a walk on the cards.’

Beth smiles again, but her eyes slip behind Kat, towards the pavement. Kat allows herself one more look, then takes Luna’s lead and turns back down the steps. ‘I’ll give her an hour on the common, then a wash at the salon, so we’ll be back around seven o’clock.’

‘Thanks, Kat, you’re a real star.’

Kat turns left towards Wandsworth Common, the closer of the two commons to Groom & Bloom. Streetlamps cast their glow over the parkland closest to the road, but Kat isn’t scared of the dark, so she heads deeper in, towards the trees. Luna clearly approves because her tail is up and wagging ferociously as she forages in the leaves. Kat watches her chase a squirrel until it disappears up a tree. But instead of losing interest, Luna sits patiently beside the trunk, nose up, waiting for it to reappear. Her unfailing optimism, against all the available evidence, feels like a message for Kat. Keep going; you failed last time, but this time will be different.