‘Just answer my questions, sir. Did you touch the lorry? Is there any reason why we might find your fingerprints on the vehicle?’

‘No,’ he said. ‘I called 999 and the police came immediately. And they said it could be a bomb.’

I lifted the POLICE DO NOT CROSS tape and held it up as a handler ducked under with her sniffer dog. The handler was a young uniformed officer, shockingly relaxed, and her dog was a brown-and-white Springer Spaniel that pulled on its lead, anxious to get cracking.

‘Good girl, Molly,’ the handler said, and we all watched the pair of them approach the lorry.

The Canine Support Unit uses the kinds of dogs who struggle to get adopted at rescue centres – high energy, endlessly curious dogs that don’t know how to stop moving. The same qualities that are all wrong in a household pet are a huge plus in a sniffer dog looking for explosive devices.

Molly sniffed the chassis of that abandoned lorry as if it was a long-stemmed rose.

I held up the tape for them when they came back.

‘What does Molly think?’ I said.

‘Molly thinks it’s not a bomb,’ the handler told me.

I scratched the dog behind the ears.

‘That’s good enough for me,’ I said.

I looked over at a slight, bespectacled woman who was standing with an armed officer whose face was entirely covered by a ballistic helmet and a balaclava.

She was holding a skinny latte from the Bar Italia – cops favour the Bar Italia because the coffee is so good and because it stays open for twenty-two hours a day – while he was holding a SIG Sauer SG 516 semi-automatic carbine assault rifle. The woman was my immediate boss, DCI Pat Whitestone, and the man must have been the commanding officer of CTU. I nodded and DCI Whitestone acknowledged the gesture with a salute of her coffee.

This was our case now.

‘Let’s open it up,’ I shouted, ducking under the perimeter tape.

A fireman from the station on Shaftesbury Avenue fell into step beside me. He grinned at me, bleary with exhaustion, and I guessed he must have been kept on after pulling the graveyard shift. Over one shoulder he carried bright red bolt cutters, four feet long, and as we reached the lorry, he swung them down and set the steel jaws against the rust-dappled lock that secured the back door.

He looked at me, nodded briefly, and put his back into it.

The cheap lock crumbled at first bite.

We both grabbed one door and pulled it open.

I stared into the darkness and the cold hit me first. The temperature in the street was in the low single digits. But in the back of that lorry, it was somewhere below freezing.

I climbed inside just as my eyes cleared.

And that is when I saw the women.