‘You should make it bloody easy on yourself and answer the questions,’ Marsden said.

‘I can’t tell you something I don’t know,’ Slack told him. ‘And beating me up won’t change that.’

Marsden whacked him again. A back-hander this time across the left side of his head.

‘Where’s the woman, Slack?’ he demanded. ‘And what happened to officer Wallis? You might as well tell us now because you will eventually. I guarantee it.’

‘Do yourself a favour and let me go,’ Slack said. ‘If it ends now I won’t say anything to anyone. You have my word.’

Marsden shook his head. ‘You’re in no position to make deals, you scummy piece of low-life. Take a look around you. See all those tools hanging from the walls? I’m sure you know from experience that most of them can be used to cause a lot of pain. Well, if you don’t tell us what we want to know you’ll soon find out what it feels like to have your teeth pulled out with pliers and your knees crushed with a hammer.’

For a fleeting moment, Slack was tempted to tell them everything, but he resisted. There was no point because they were going to hurt him no matter what he said or didn’t say.

This was their chance to get revenge for what had happened to their colleagues and the Commissioner. Their chance to show him that no villain was a match for the mighty Met.

And yet there was an irony here that would be lost on them. He was sure of that. It wouldn’t occur to them that their actions would only serve to justify what he had done to them.

It showed that they represented an institution that was rotten to the core, peopled by an army of bent coppers who were prepared to break the laws they were meant to uphold whenever it suited them. And this scrawny little shit of a detective who was trying to act tough was a prime example of those who deserved to suffer a whole lot of pain and humiliation.

‘Tell you what, detective,’ he said. ‘Why don’t you get one of those hammers down from the wall and shove it up your arse? Or better still get one of those idiots in their stupid masks to get a set of pliers and cut off your limp, little cock?’

Marsden let rip then. He drove two more punches into Slack’s face and one into his stomach. As Slack yelped in pain, the detective stepped back. But there was no respite because one of Marsden’s accomplices then struck from behind, slamming his knuckles into the back of Slack’s neck.

None of the blows was hard enough to knock him out, which meant he had to endure excruciating pain and the feeling that his head was flying off into orbit.