Chadwick’s heart began to race. He tried to move but found himself still paralysed. He stared back at the eyes, which were now wide with excitement, and he could sense a smile beneath the mask.

Then came something new. Something awful. It was at once white-hot and ice cold, a pin prick of intense pressure that seemed to pierce downwards, moving deep inside him, becoming more and more agonizing by the second. The pain was like nothing he had ever known. He felt his skin tearing, his muscles ripping, as the razor-sharp surgical scalpel sliced into him. He felt the fountains of warm blood spilling out over his sides, the pinch of cold air against his exposed internal organs. Chadwick tried to open his mouth and scream, but no sound came out.

The hands were deep inside him now, pulling, twisting and wrenching his organs apart. It couldn’t be happening, but it was. He was being cut open by someone who was only too well aware that he was still awake. This was no mistake, this was no innocent error. He was witnessing his own cold-blooded murder.

The voice that had once gently called his name was now breathless with excitement. The sound of euphoric laughter was still ringing in Chadwick’s ears as the life seeped out of him and the bright lights slowly faded into absolute, eternal darkness.

1

‘I know the drill.’

Detective Chief Inspector Neil Barker looked across the table and stared hard at the stern-faced woman sitting opposite him. ‘Then you know that we have to go through it anyway,’ he said, trying hard to hide his irritation. Then, as he looked around the room, his face seemed to soften slightly. ‘Listen,’ he said quietly. ‘No one likes being on the receiving end of all this. Let’s just get through it as best we can.’

‘Whatever,’ came the surly reply.

DCI Barker shuffled the sheaf of papers in his hands, cleared his throat and began. ‘For the benefit of the tape, please state your full name, your warrant number and the unit to which you are currently attached.’

‘Stacey Elizabeth Collins. 177265. MIT South.’

‘Thank you. I am Detective Chief Inspector Neil Barker, attached to the Anti-Corruption Unit of the Directorate of Professional Standards. My colleague is …’

Barker switched his gaze to the black woman in the neat grey trouser suit sitting on his right.

‘Detective Inspector Karen Willis, also attached to the Directorate of Professional Standards.’

‘Also present on behalf of DI Collins is a Federation representative. Could you introduce yourself?’

‘Alan Matheson. Police Sergeant 383, posted at Plumstead Police Station.’

‘Thank you,’ said Barker, nodding in the man’s direction. He then twisted his body to face the middle-aged man behind him. ‘And the final person in the room is …’

The man leaned forward so his soft Scottish accent would carry across to the microphone. ‘Detective Chief Inspector Warren Milton. Serious Organized Crime Agency.’

Barker turned back and continued. ‘The date is Thursday, 13 May, and the time by my watch is now 5.32 p.m. We are in an interview room at Peckham Police Station. At the conclusion of this interview I will explain the procedure for dealing with the tapes and your access to them. Do you understand?’

Collins raised her eyes to the grey-flecked tiles of the suspended ceiling. ‘Of course.’

‘Before I say anything further I will caution you that you do not have to say anything but it may harm your defence if you do not mention when questioned something which you later rely on in court. Anything you do say may be given in evidence. Do you understand?’

Collins understood only too well. After eighteen years in the police force she had given the same warning on hundreds of occasions – every time she made an arrest. And, as one of the Met’s leading detectives, Collins made more arrests than most. This was the first time she had ever found herself on the opposite side of the interview desk, and it was an experience she would have happily gone without.

Normally she would have been sitting in one of the comfortable wooden chairs, not the flimsy plastic one that flexed every time she moved and was almost impossible to relax in. It was, of course, just one of a number of ploys used to give officers an edge over suspects during interviews.

Don’t rise to the bait. Don’t let them get to you.

‘I understand,’ Collins said softly.

‘Then let us proceed.’ Barker jerked his head towards Willis, who opened a slim manila envelope and pulled out a series of grainy colour photographs. She slid the first across the table towards Collins. ‘This was taken by SO11 officers involved in long-term surveillance of the main target in a drug-trafficking investigation,’ she said. ‘You will see there is an obvious cause for concern. This is your chance to explain.’

Collins glanced down at the print and needed no time at all to take in all its details. After all she was in it. She had lived it. Taken at dusk using a powerful telephoto lens, the photograph showed her speaking to a man called Jack Stanley in a park near the ruins of an old manor house in Chiselhurst, Kent.

Collins had known Stanley for just about as long as she had known anyone in her entire life. And for just about as long as she had known him, Jack Stanley had been on the wrong side of the law. Over the years he had progressed from a petty criminal on the Blenheim Estate, where he and Collins had grown up, to a leading figure in the South London criminal underworld.

When Collins joined the police service she quickly reached an agreement with her childhood friend. Stanley provided her with tips about the activities of drug gangs and armed robbers, and even helped her to recover stolen goods. In return Stanley received subtle hints about potential police investigations into his growing criminal empire and detailed explanations about the latest forensic techniques that might be used against him.

It was a covenant with the Devil that saw Collins’s career go from strength to strength as she developed a reputation as an outstanding and highly effective officer, but Stanley benefited even more. The majority of his tip-offs led to arrests of members of rival gangs who were trying to muscle in on his patch, thus clearing the way for his own people.

What Stanley didn’t know was that Collins had, for the most part, always managed to avoid doing anything illegal. The hints about police investigations amounted to little more than underworld gossip, while details of new techniques and technology could all be found in publicly available sources, just so long as you looked hard enough. But there were plenty of times when Collins sailed too close to the line or briefly stepped over it. It was, she told herself time and time again, the only way she could do her job. It was a necessary evil.

Collins cut her ties with Stanley soon after he was arrested as the prime suspect in a gangland slaying. He was acquitted after all the key prosecution witnesses suddenly and mysteriously withdrew their statements and developed collective amnesia. In the years that followed, Collins always knew there would come a time when their paths crossed once more.

The meeting in the park where the photographs had been taken was the first time they had seen one another in several years. Collins had run into a brick wall while investigating the case of a young boy named Daniel Eliot, who had been kidnapped and murdered. Thanks to his criminal contacts, Stanley had been able to help out, but in return he had wanted Collins to help him uncover an informant in his organization. Collins had refused point blank, as it was clear that Stanley would have immediately had the grass executed and Collins didn’t want blood on her hands. But soon afterwards her daughter, Sophie, had gone missing and she had needed Stanley’s help once more.