‘It is beautiful,’ she agreed. She shivered, and pulled her jacket closer around her.

‘Do you want mine?’

‘I’m fine.’

Two middle-aged tourists stopped, asking for directions. Ed pointed, explained, smiling easily, No, it’s no trouble.

Casey waited.

‘I’m not coming because of that business with Declan yesterday,’ he said at last.

‘OK.’ Casey felt the gloom settle around her. Checkmate.

A fat spaniel waddled past. A father, impatient, scooped up his toddler son and marched down the hill, ignoring the bawls. It had rained recently, black puddles sprinkling the maze of paths.

‘You talked about turning a blind eye,’ said Ed.

‘What?’ Casey’s memory blurred. ‘When?’

‘Down on Southbank. You said that I’d regret turning a blind eye to those girls.’

‘Oh,’ Casey remembered. ‘I’m sorry about that. I know you . . .’

‘I can’t stop thinking . . .’ He paused. ‘I’ve never told anyone . . . We never spoke about . . .’

‘Spoke about what?’

‘Afghanistan,’ Ed said. ‘My unit was out there with the ANA,’ he went on. ‘The Afghan army.’

‘Yes.’ She kept her voice even.

‘We were sent out to a small base, not far from Bastion. Just a dot on the map.’

Casey waited.

‘And then we were stuck there for weeks on end.’

Casey remembered those bases, out in the wilderness. The Chinooks screaming in low, ducking and diving, racing scared of the missiles. She remembered the patchwork of canals, the scrappy little villages, the fluttering pink of the poppies. The smiles from the locals that weren’t smiles at all. And the patrols through the fields, against every instinct, when the danger is so real that it must be ignored.

‘We were training the Afghan soldiers out on that base,’ he said. ‘We were working with them. Alongside them.’

‘Yes.’

‘We needed their help. We couldn’t do it alone. There were too many Taliban. Too many enemies.’

‘I know.’

‘We had to get the Afghan security forces trained up, so that we could leave. That bloody country . . . But we needed to leave a decent force behind.’

‘I remember.’

‘So we were working with the Afghans, day after day. Teaching them what they had to know. And giving them guns, of course.’

Casey remembered the monotony on those bases: the endless rules, the hours on stag, the crunch of the boots on the gravel. She remembered the men waiting for orders. And the boredom, and the high bombproof walls, as the world got smaller and smaller.

When the only interesting thing is: you might die today.

‘We were miles from everything,’ said Ed. ‘It felt like we were completely alone. Just us, forgotten. The Afghans were fed up too. They’d had enough.’

For a second, oddly, Casey remembered the latrines where everything was bagged and incinerated, as if they were never really there at all. The smell, swallowing you whole.

‘Some of the Afghans, at night . . .’