I showed him my warrant card. He peered at it and nodded. Then carried on with what he was doing. Whatever you do, get their name and address, they tell you at Hendon. It’s the very first thing they tell you.

‘May I ask your name, sir?’

‘I’m nobody. I’m just the groundsman.’

A strange accent that contained both Eastern Europe and the West Country. I watched him unload the wheelbarrow. There was something wrong with his hands. He glanced at me and saw that I was still waiting for an answer.

‘Len Zukov,’ he said.

‘Where you from, Len?’

He gave me a sharp look. ‘I’m from here. How about you? Where you from?’

The accent was Russian, maybe.

‘I’m from here, too,’ I said.

‘Then we’re both from here.’

‘Worked here long, Len?’

He was silent for a moment, as if adding it up.

‘Thirty years,’ he said.

‘Do you remember these boys?’

I was holding out a photograph of the seven boys in their Combined Cadet Force uniforms.

He shook his head. Too quickly?

‘Many boys come and go,’ he said.

‘This was taken in 1988. In your time. You don’t remember them? Have a closer look. The King twins? You don’t remember identical twins?’

‘No.’

The worst thing about being a policeman? People lie to you. They lie all the time. They lie because they are afraid of getting into trouble, they lie because they are afraid of getting into deeper trouble, and most of all they lie so that you will go away.

But maybe he was telling the truth. It was a long time ago, and boys had come and gone in their thousands.

‘But you know Mr Philips,’ I said. ‘The sports master. And you know that someone tried to kill him.’

The old man looked at me as if I was some kind of idiot.

‘Everybody knows,’ he said.

I watched him load more leaves on the fire and then saw what was wrong with his hands. The fingers did not open. He was building his fire with two fists closed by what looked like the advanced stages of rheumatoid arthritis.

‘It was in the woods,’ he said. ‘Far from here.’

When the last of the leaves were on the fire he brushed his closed fists on his trousers and we walked to the front of the cottage. There was a figure standing in the doorway – the physiotherapist Mallory and I had seen on the playing fields with the disabled men. Now I saw that he was not wearing a mask. Most of his face had been lost to burns.

I held out my hand.

‘Sergeant Tom Monk,’ he said. ‘Formerly of the Royal Green Jackets.’