‘Too late for that,’ he muttered.

‘It doesn’t have to be. You can still have a life, Sergeant Trevelyan. You can get out of here, and go back to your family, and be surrounded by people who love you.’

‘Even if I don’t deserve it?’

Dulcie sank down on the chair beside his bed. She knew she would get an earful from Miss Sutton if she were caught sitting down on duty, but she didn’t care. At that moment it seemed there were bigger matters to worry about.

‘What makes you say that?’ she asked. ‘What did you do that was so bad you can’t face your family, Sergeant?’

He was silent for a long time. Dulcie was just about to give up when he murmured something under his breath.

She leaned forward. ‘What did you say?’

He turned to look at her, his pupils so wide they turned his green eyes black.

‘I said, I killed a man,’ he said quietly.

For a moment she wondered if she had misheard him again.

She searched for the right words. ‘All the men on this ward have killed someone, Sergeant. It’s awful, but it’s the war, isn’t it?’

He sent her an almost pitying look. ‘You don’t understand,’ he said. ‘This wasn’t some German in No Man’s Land. This was one of our own.’

‘He was only a kid. Sixteen years old, only four years older than my son. He lied about his age because he wanted to fight for his country.’

Sam spoke in a flat voice. He didn’t look at Dulcie, but stared instead into space, as if he was describing a scene that was playing out in front of him.

‘Trouble is, he didn’t know what he was signing up for. No one did. You can’t make people understand if they weren’t there. You can describe the trenches knee-deep in water and running with rats, and the cold, and the noise of the shells, and the stink of dead bodies heaped up and rotting because no one has time or a place to bury them. But until you’ve lived through it …’ He shook his head. ‘It was too much for anyone, and too much for this lad. He’d just watched his best pal die, you see. Right next to him. One minute they were sharing a cigarette, the next a shell hit and this lad was picking bits of his mate’s skull off his gas cape. And that wasn’t even unusual, it happened all the time …’

He stopped for a moment, and Dulcie could see him struggling to gather himself.

‘Anyway, this boy took fright. When we got our orders from down the line, he decided to make a run for it instead. He went into hiding, down in the sappers’ tunnels. But they found him and brought him back.’

He turned to Dulcie for the first time. ‘I couldn’t blame him,’ he said. ‘When you get the orders to go over, you know that’s probably it for you. You hear that whistle blow, and you know you have to scramble up that ladder and fight your way through the mud and barbed wire. And then you have to walk – actually walk – into the artillery fire, with shells exploding all around. No wonder half the men in here are doolally. And they’re the lucky ones!’