The glass on the front of Breitner House is a forbidding jet black. Even seeing the owner’s name above the door gives me a shiver. The security guard checks Wilkinson’s pass, types my name into his computer and waves us through the bank of turnstiles.

Upstairs, the newsroom is not quite empty. A brace of night editors will stay almost until dawn, until it’s too late to slip a late-breaking story into a very last edition. One, to my surprise, is doing The Times crossword. The other is reading Proust, the Scott Moncreiff translation in its famous sky-blue jacket. Really.

Wilkinson greets them. ‘I need to have a quiet word with young fellow-me-lad here. Can you toddle off for ten minutes and take a fag break?’

They don’t need telling twice and walk to the river side of the office into a communal room containing a coffee machine.

‘Right,’ says Wilkinson, taking two large keys from a desk drawer. I follow him over to the safe I saw before, where he kept the photographs of Clare and Jeremy. His hands show a slight tremor and it takes him a moment of fiddling with the keys and cursing under his breath to open the heavy steel door.

While he’s distracted, I reach into my pocket. I don’t dare take out the phone in case he notices, but I redial the last number I called. Jess’s. I place my finger over the small speaker, so that when she says hello, KT can’t hear.

Before he opens the door, I say in a very loud voice – which I hope Jess can hear – ‘I’m dying for a cigarette. Could I bum one?’

Wilkinson chucks the packet at me, and his Bic lighter, and then returns to the safe. While his back is turned, I take the phone out of my pocket, note that Jess seems to be on the line and hang up.

The safe swings open.

‘The crown jewels,’ says Wilkinson with a flourish. ‘You can look, but no touching.’

The safe has two shelves. On the top are a series of manilla folders, some bulging with documents and photos, others so slim I wonder if there’s anything inside. Wilkinson can see me gawping. ‘Sadly if I told you what’s in these, I’d have to kill you. But take it from me, if most of this stuff became public, some of the most famous and revered people in the country would struggle to find work on the buses.’

On the bottom shelf is a scruffy wooden box made out of plywood. Wilkinson pulls it out and lifts the lid. There are piles of banknotes inside it: tens, twenties and fifties, some crisp and new, others dirty and creased, rubber-banded into bundles. Thousands of pounds. And wedged down the side is an old-fashioned, slightly worn red ledger, the sort you can buy for a couple of quid in WH Smith.