Here we go. ‘I want to make some enquiries,’ Robin said. ‘Independently.’

‘You don’t trust the police.’ Not a question, a statement.

Careful, careful. ‘It’s not that. But I think there’s a chance, knowing them as well as I do, Rin and Josh, that I might pick up on something the police would miss.’

‘Would you tell them you’re doing it?’

‘No.’ The word echoed. ‘More than that, Kath, I’d ask you not to. I can’t risk it. I’m going to appeal my dismissal and if the Met get wind that I’ve been poking around in a case …’

Kath eyeballed her. ‘And if you find something?’

‘Then I’ll suck up the consequences and take it to them straight away. At that point, they’d go easy on me, I think. I hope.’

On her way out, Robin paused at the bottom of the stairs, her eye caught by an angle of greenish light slanting through a door across the hall. Back then, the room had been Gerry’s study, the strange underwater light made by a big laurel outside the window. On Rin’s wedding day, she’d entrusted Lennie to Hilary and hidden in there for a few minutes to let the rictus drop off her face. It had been cool and serene, she remembered, fitted bookshelves and minimal furniture, just an armchair, a standard lamp and the table Gerry used as a desk, its top covered with papers. She’d found it steadying that day, a reminder of the real world, the refuge of work. This, too, shall pass. She remembered something else. ‘Kath, do you still have that wall of photos?’

‘Yes, of course. Do you want to see it?’

‘Can I, quickly?’

Kath opened the door. ‘It’s still Dad’s study, probably hasn’t changed much since the last time you were here. Though he’s taken up genealogy in a major way since he retired so excuse the piles and piles of bad photocopies. If you need to know what we were doing during the Civil War, he’s the man to ask. Though if you’ve got any kind of boredom threshold, I wouldn’t.’

The furniture had been moved since the wedding, to maximize light, Robin guessed: the desk with its messy heaps of paper was by the window now, the armchair positioned directly under the lamp. It was instantly recognizable as an old person’s workspace, and not just by the magnifying glass on the mousepad and the dated desktop computer. Here were the treasures of a lifetime: a framed photograph of Gerry and Hilary somewhere hot, another of Kath and Josh as blunt-fringed Eighties toddlers in a paddling pool on the lawn. A pebble paperweight painted with a childish snail, a home-made papier mâché matchbox cover.