I picked up the phone before it could ring again and held it silently to my ear, listening as hard as I could. Background noises. The sound of someone breathing. Faint traffic noise, wind blowing, a siren, distant and almost inaudible. He was taking the call outside, in the open air, maybe in the street or in a car park. We were connected at either end of this electronic silence, but separated in every other way possible. We might be a thousand miles away from each other. Or a few metres away.

He could be watching me right now.

‘Hello?’ I said quietly, pitching my voice low.

The silence stretched out further. Five seconds. Ten. I was about to speak again, but held back. Don’t show your hand.

A click, and the line went dead.

Instantly, I regretted my silence.

‘Don’t hang up,’ I said to the dial tone. ‘You bastard, don’t hang up!’

I smashed the phone back into its cradle. In the distance, a siren sounded, and I had a sudden irrational sense that I’d heard it moments before, down the phone line. It felt like we were close, in the same neighbourhood. As if Ben was nearby.

So close.

The sound of teenagers sniggering reached me from outside the booth. I ignored them and rang the number straight back, using my last 20p. This time it rang six times and went to a computerised voice asking me to leave a message. Instinct told me not to. I hung up.

There was still one number left on the list. It was the most puzzling of all: the escort agency. But all my coins were used up. My wallet was empty. There was a cashpoint down the street, but then Ryley Warner and his mates would claim this one remaining phone booth. And I couldn’t stop now.

Screw it. I took my mobile out and dialled the last number, with only the germ of an idea of what I might say. It rang four times and went to voicemail, a woman’s voice, husky and deep.

Hello, you’re through to VIP Escort Services, you’re just one chat away from the most sensational night of your life. Leave your number and we promise to call you right back.

I hung up, not wanting to leave my name on their answering machine.

The last number I dialled wasn’t on the list and hadn’t been on the secret phone in Mel’s handbag, but that didn’t matter – I’d known it by heart for years. I knew it better than my own.

I sat on a bench in Regent’s Park, hands in my pockets against the cold, watching the joggers as they circled the lake. The water was grey and choppy with the autumn wind, a cluster of tired-looking rowing boats tied up and covered for winter next to the café.