‘Only if he discovers that the wrong person died thirty years ago. He was part of the process that identified Kelly in the first place, so he should know that that conviction was secure then and remains so now.’

Tony waited a beat before he spoke. ‘And what if he discovers that Kelly shouldn’t have died?’

‘Then we have a problem,’ Mullan said. ‘Hugh’s an attack dog. That’s how he thinks. It’s like you said; he’s threatening. That’s what dogs do, they growl. It’s how they’re trained.’

‘I can hear you,’ Duggan said.

‘I assumed you could, Hugh,’ Mullan said. ‘You know it’s true. That’s what you were good at.’

‘While you sat back giving orders, not wanted to get your hands dirty.’

Mullan accepted the criticism with a nod. ‘Why keep a dog and bark yourself?’

Tony wondered at his calmness. Mullan continued moving through the woodland, stepping over tangles of brambles and weeds which covered the ground in areas where the sun was able to break the canopy, as if he already knew the location to which they were going, the end to which they were being drawn. Tony, for his part, knew different. They had killed the wrong person. That truth had yet to be revealed.

‘I’m no dog,’ Hugh snapped.

‘You’re a good man, Hugh,’ Mullan said. ‘But you’re wrong in this.’

‘Someone lied to us,’ Duggan said. ‘In Betty’s that morning. Someone lied.’

‘About what?’

‘About Martin. Everyone confesses, Doherty said. But Martin didn’t. No matter what was done to him.’

‘Martin was a special case,’ Mullan said. ‘He’d been lifted on and off for years by the cops for dealing. Hell, even the first time we spoke to him in Derry, after we caught him red-handed, selling, he denied it to my face. He had a skill in lying. It was useful in its way, but you couldn’t trust him. Not in the slightest.’

‘I trusted him,’ Duggan said. ‘He was always straight with me.’

‘Lie with dogs and you’ll catch fleas,’ Mullan muttered.

‘What the hell is that supposed to mean?’ Duggan snapped, but Mullan walked on and did not respond.

Karen stopped and surveyed around her, turning her head slowly from side to side, searching for something that might trigger recognition. ‘Are you sure this is the right way?’

‘Yes,’ Duggan said, though without his earlier confidence.

‘I don’t remember any of this,’ Tony said.

‘I wouldn’t remember it anyway,’ Karen said. ‘It was dark. We were almost delirious.’

‘There was a tree trunk, a stream,’ Tony said. ‘We crossed it about half way through.’

‘Maybe it’s rotted,’ Mullan said. ‘The stream dried up.’

‘The track of it will be there,’ Duggan said. ‘The memory of it.’