I trudged up the long driveway to the prison entrance, aware of officers dotted at intervals along the perimeter fence. There would be no escape from the bleak surroundings. Oliver’s hulk wouldn’t be able to slither along tunnels and any attempt to scale the fence would be futile. It would collapse under his weight.

When I reached the entrance portico, a nameless prison official thrust an arrival form for me to sign before I was led through to the visitors’ room. I waited at a Formica-topped table until the minute hand worked its way round to midday. A large black-framed clock stared down from the wall; a reminder of time, the essence of prison.

The room was painted a dull grey. No merry murals of seascapes or mountain vistas. The walls reminded visitors of why they were here and of crimes committed. I picked at a scab on the inside of my forearm which I’d released from the confines of a woollen jumper. A prison officer stood, a silent statue, next to the door, waiting for it to open.

When Oliver appeared he didn’t seem to know who was visiting and after a swift glance round the room, turned to head back the way he’d come. The guard tapped him on the shoulder and pointed. I stood up, smiled and held my hand up in silent acknowledgement. He walked over and sat down opposite me.

‘Oliver, I don’t know what to say,’ I began. If Mitch’s bludgeoning to death had rocked me to the core, Oliver appeared to be in a catatonic state, barely able to speak. After a moment’s silence, he said my name.

‘Amber, it’s nice to see you.’ We could have been meeting on the High Street after a number of years, swapping pleasantries. There was no familiar hint of a playful grin on Oliver’s lips. He looked down at his hands, which seemed even larger than I remembered as they splayed out across the table.

‘I know you didn’t do it. I know you didn’t murder Mitch. That’s why I’m here,’ I said. I folded my hand over his flattened fingers, giving them a reassuring squeeze. ‘Rebecca killed Mitch. I’m certain and I’m going to prove it but I’ll need your help.’

Oliver’s eyelids twitched, and he blinked hard to contain a tic that beat in his left eye.