The desk is empty, apart from a few pencil shavings and an empty biscuit packet. If there was something here, the people Dolly saw must have cleared it out.

I scrabble back to the kitchen. Jess is crouched in the middle of the room, surrounded by stinking rubbish. By the light filtering in from the hallway, I can see takeaway boxes, napkins stained with the fat of doner kebabs and burgers, empty beer cans and mouldy bread. She’s emptied the whole kitchen bin onto the floor. The stench is so strong it makes me gag.

I have dragged Jess here in the dead of night, made her an accomplice in a crime, and here she is up to her elbows in this shit. ‘I don’t deserve a friend like you,’ I mutter.

I’ve embarrassed her. ‘You are so right. And you are definitely going to want to see what I’ve found.’

With a look of triumph, her hand comes up holding a filthy envelope, which she hands to me. I take it between finger and thumb, curiosity outweighing the stab of revulsion at the thought of all the bacteria I am touching.

For a moment I can’t think what she’s on about. There’s no writing on the envelope, no address or postmark. Nothing that would tell us anything.

Then I see the logo in the bottom left corner, just under my thumb. A globe spinning on its axis, with the continents picked out in spidery lines, stained and blurry through contact with a teabag.

It takes me a minute to clock what I’m seeing. It’s not in its natural habitat; usually, you’d find it bigger and bolder at the top left of a newspaper front page, next to a thick red stripe behind bold white print.

Flipping fuck!

‘That’s a Globe envelope.’

Jess and I stare at each other in silence. I think of the people Dolly saw who came to this house, the couple who spent an hour inside, presumably emptying the desk and erasing any trace of Deyna, the threesome who came in the car registered to Media Corp. They must have overlooked the kitchen bin, either because they were put off by the smell or saw it filled with dead takeaways.

It’s the missing piece. At last I can prove a direct line from Breitner to the man who killed Clare, via one of his newspapers and a dingy house off Green Lanes. And maybe because we’ve at last made a breakthrough, and are so close to finishing Clare’s work, I become frightened. Properly scared.

A siren breaks the silence in the house. Not near, but it sounds as if it’s coming towards us.

‘We should get out of here,’ I say.

‘I never wanted to be here in the first place.’