She suspects that Ajay has already sent over the results to Rob and that Rob is just humouring her.

‘That’s great news,’ he says. ‘I said you were improving.’

‘I guess so,’ she replies, looking forlornly at her half-finished painting of Stretch.

After a quick chat – Rob interrupted a work call to take hers – she lets him go. Stretch has not returned. She walks down the long corridor, eating a piece of Yarg. At the far end, it’s right to the big spare bedroom, where Bex always stays, or left to a storeroom. Where’s Stretch gone?

She stops in her tracks. The door to the storeroom is open. That’s a first. It’s been locked ever since she’s been here. Rob’s got an obsession with laptops and computers and once told her he keeps quite a few of them in the storeroom for security. The whole house is very safe – security lights and cameras everywhere, triple locks on the outside doors. Kate told him it wasn’t necessary, but he installed them soon after she moved in, thought she was being naive about her previous life, the nature of her police work.

Stretch appears in the doorway.

‘What are you doing in there?’ she says, as if it’s his idea to be nosy.

She follows him through the door. It’s more of an office than a storeroom, dominated by a large black desk and a picture on the wall behind. In the corner there’s a stack of old laptops, at least ten of them. There are no windows, which is out of keeping with the rest of the light-flooded house. The back wall is cut into the hillside and the front wall adjoins the guest room.

‘Bigger than we thought, isn’t it?’ she says to Stretch, switching on the main light. ‘Much bigger.’

She walks around the workstation, running her finger across the smooth black marble. There’s a computer screen on the desk, flanked by soundstick speakers, but it’s the black-and-white picture propped up against the wall that catches her attention, even though it’s partially hidden by some card and wrapping.

She lifts it up, blows off the dust and studies it more closely, her head spinning. It looks pre-Raphaelite and has been done in pen and ink and brush. The inscription in the corner says ‘DGR’ – Dante Gabriel Rossetti. A couple dressed in medieval clothes are walking through woodland. They appear to have stumbled across their doubles, identical in every respect: same physical features, medieval clothing, matching feathers in their caps. The woman has fainted and her terrified man has drawn a sword to confront his double, staring into the whites of his eyes. The only thing that distinguishes them is that the couple on the left has been framed with an ethereal glowing light, to denote that they’re the doppelgängers.

If only it were that easy.