Milligan let go of Silva’s arm. He stared down at the asphalt path. The surface was dotted with the white blotches of discarded chewing gum and he moved his right foot and scuffed at a piece. After a moment he looked up, his face drained of colour.

‘I’ve got three children, Rebecca. They walk half a mile to school and back every day. Do you know how easy it would be for a car to mount the kerb and run them over? How easy it would be for someone to sweep past and throw acid at them? I’m not easily frightened, but I couldn’t live with myself if…’ Milligan’s words trailed off as he looked across to an elaborate tomb where a cherub stood on a plinth. ‘I’ve resisted pressure before but that’s always come from big business or hapless politicians or tinpot dictators. This is different. This is much, much bigger. Global.’

‘Global?’ Silva was thrown. Milligan was opening up but now she was wondering if he was slipping into fantasy. ‘Are you saying there’s some kind of conspiracy?’

‘Yes.’ Milligan gulped and swallowed. Sweat beaded on his forehead as if he had a fever. ‘Too many people have too much riding on this to contemplate the alternative. I’ve always believed in speaking truth to power, but the power in this case is too strong. I can’t fight against them without losing everything.’

‘Does anyone else have the story?’

‘There is no story. I’ve told you nothing, Rebecca, nothing, understand?’

‘At least tell me what happened to my mother’s files so I can follow this up.’

Milligan glanced round, scanning the shadows under the trees. He stepped off the path, beckoned Silva to follow and darted away into a stand of thick laurel. Silva jogged after him and pushed under a tangle of branches into a little clearing. Milligan stood on the far side. He held his hands up.

‘Stop.’ He clenched his fists, fighting something internally before letting his hands fall to his sides. ‘This is all I tell you, OK? You promise you won’t try to contact me again? Promise you won’t tell anybody we met?’

‘I promise,’ Silva said.

‘The laptop was taken away by a couple of intelligence officers. They said it contained evidence that would help them track down the terrorists. When I logged on to our system and tried to discover what happened to the files your mother had backed up to the cloud, I found nothing. All the material had been deleted without trace.’

‘But—’

‘That’s it. I don’t want to hear another word.’ Milligan stepped away. ‘We can’t meet again, not alone like this. It’s too risky.’

‘Neil, you’ve got to help me get to the truth!’