‘My God,’ Cooper said. ‘So Liz Grafton wasn’t kidnapped at all.’

While Mac sent a text, he said: ‘It seems not. But we don’t assume anything, okay? Seabury could have killed her, and he could say she ran off again.’ Cooper nodded. ‘One other thing. From now on, leave the talking to me. You mentioned Ronald Grafton to Seabury’s wife.’

Cooper looked puzzled.

‘She’s worried about her husband. And now she has a name to use on the Internet. She’ll find out that Karl’s being hunted by killers. A pregnant woman doesn’t need that sort of worry.’

‘I’m sorry.’

‘You’re still learning. Pull that surveillance off Seabury’s house.’

Cooper said: ‘Really? What if he—?’

‘He won’t come back, Cooper. He’s going straight to a police station. I’ve been around longer than you, and my hunch tells me that. You’ll develop one in a few years, and you’ll trust it. Heck, even if he did come back, he’d sit tight, hug his wife and call us.’

Mac’s phoned pinged. A return text.

‘He could be a dangerous man,’ Cooper said. ‘If he comes back, we should grab—’

‘We won’t grab him. He’s a surveillance expert, Cooper. He’d know we were watching. And then he’d lose trust and carry on running. This guy isn’t a hardened killer. What happened with Król was self-defence. He’s a scared man. He’ll go straight to a station, believe me. Half an hour from now he’ll be in custody. Pull the surveillance. It’s a waste of manpower.’

Cooper made no move to do so. ‘Your informant, is he working for these people? He ever mentioned Ronald Grafton to you?’

‘Informants all have secrets. I had no idea. But we’re assuming again, aren’t we? Leave the fucking thinking to me, okay?’

Cooper, frustrated at being shot down again, opened his mouth to speak, but Mac held up a hand as his phoned pinged once more, and he glanced at the screen.

‘I’m sorry I spoke that way to you,’ Mac said to Cooper, locking his phone. ‘You’re a good copper,’ he added.

He was putting the phone away when it rang. He was smiling when he removed it from his jacket, thinking it was the same caller as before. But his smile disappeared when he saw the name of the caller. He almost put the phone to his bad ear again, but realised his error just in time. It was still hurting from when he made that mistake earlier.

‘Our Nancy-boy leg-breaker is called Brad Smithfield,’ Gondal said.

‘I know him! I investigated that bastard three years ago.’

But Gondal already knew the background: a guy had been found outside a tower block late one night. Dead by cerebral ischemia: insufficient blood to the brain. Turned out to be a guy affectionately known as Rocker, because he was off his. He was an enforcer employed by an Edinburgh crime figure called Razor Randolph. He’d been investigating a robbery at Grafton’s nightclub, in which two masked men had burst in, shot the place up, and fired rounds at Randolph as he and his men sat in a booth with Grafton and his cronies.

The cops had looked at the residents. Brad Smithfield was a career criminal with a plethora of small convictions, one of which had been for choking a guy unconscious. And a stranglehold could cause cerebral ischemia – it was too coincidental. He was visited immediately, and the police thought they had their story: Rocker had information that Smithfield might have been one of the shooters and had decided to pay a visit. Good information, because he was soon dead. The CCTV had been busted in the flats for weeks, and in that area of Erith in Bexley the cops faced a wall of silence when seeking witnesses. A search of Smithfield’s flat yielded no evidence. No arrest. No one was ever charged with the killing.

‘I bet it was him,’ Gondal said. ‘The police missed something.’

‘I led that investigation,’ Mac said. ‘He was fully assessed, and interviewed. I missed nothing.’

‘I got his address. Nobody home, though. It’s owned by a guy called Ian Barker, Smithfield’s boyfriend. I’ve just got hold of his place of work, so—’

‘Don’t go there,’ Mac said. ‘We don’t want him telling Smithfield that the police are after him. This guy could go underground. Leave the boyfriend out of it. Keep watching the house. But let’s not throw everything including the kitchen sink at this guy. Remember his name came from that scumbag Ramirez. Smithfield wasn’t the only guy the Scottish mob were after. They had dozens of names. We’ve got dozens ourselves to check up on. We don’t listen to rumours, especially from criminals who might have their own reasons for giving people up.’

He hung up and told Cooper to drive him back to his car. He had a new lead to follow, he told him. It should take him about three hours.