That only made her cry harder. I found a pack of tissues in her handbag and handed one to her, waiting for the sobbing to subside a little.

‘Mel?’

‘Yes?’

‘I want you to ring him.’

She looked startled, dabbing her eyes.

‘Now?’

‘Now.’ I handed her the phone.

‘I’m not even sure it’ll have any charge left, it’s been off for quite a few days.’

‘Give it a try.’

She turned it on and put in her passcode, the one I’d guessed last night. The screen came to life, showing the battery was at eighteen per cent. She selected the address book, picked Ben’s mobile number, her finger hovering over the green call icon.

‘Are you sure?’ she said.

I nodded.

‘And put it on loudspeaker.’

She hit call and selected the speaker option.

Two rings, then it was picked up. I thought I could hear the same faint background noises, traffic noises, steady breathing, that I had heard in the phone booth an hour ago.

Mel looked at me, eyebrows raised in a question.

I nodded again.

‘Ben?’ she said into the phone. ‘Are you there?’

No answer. But a rustling noise, a click.

‘Ben? Talk to me. Please.’

Another click, and the line went dead.

Mel breathed out a big sigh.

‘Try again,’ I said.

Six rings this time. No pick-up. It clicked into voicemail, the automated Stepford Wives voice asking us to leave a message. Mel left a brief one asking Ben to call her back, and hung up.

‘What now?’ she said.

I slipped the little Samsung phone into my jacket pocket.

‘I’m going to keep this for the time being.’

‘OK. Maybe you should give it to the police or something? It might help them to find Ben.’

‘Good idea.’

‘I’m sorry, Joe. So sorry.’

I gestured towards the lake.

‘Remember when I took you out on that rowing boat, nine years ago?’

‘Of course,’ she said in a soft voice.

‘You nearly tipped us both into the water.’

‘I didn’t mean to.’

I held her to me, rubbing her arm gently against the cold, breathing in the wonderful soft scent of her hair.

‘Thought you were going to jump out and swim for it before I could get it on your finger.’

She smiled, sadly.

‘Not in that water, darling. It’s only three feet deep.’

‘I’ve been thinking, with it being our tenth wedding anniversary coming up, I was going to get you a proper-sized engagement ring to replace the one I gave you that day. It was all I could afford at the time, and I know you like it, but I’d like to get you a new one. For a fresh start. Draw a line under everything and just start again. What do you –’

‘Joe.’ She said it abruptly, cutting me off. Her face was paler than ever.

‘Yes?’