Bolt and Mo showed their ID to the uniform, who managed to finish chewing his baguette long enough to point them to a van where they could put on the plastic coveralls all officers were obliged to wear when entering crime scenes. Once they were kitted up, they slipped under the scene-of-crime tape and walked along a specially marked path lined with more tape in the direction of the tent.

Bolt was aware that his breathing had increased. He'd always feared death, right from childhood, because he'd never been able to believe – and God knows he'd tried – that there was anything beyond it. Unfortunately, because of his job, he'd had to see far more of it than most people, and almost always when the end had come violently. The sight of their empty faces was something he'd never got used to, and the prospect of seeing someone he knew and cared about lying there was much worse.

'I can do this if you want, boss,' said Mo quietly, turning his way.

Months earlier, when they'd been sharing one too many beers at a pub near SOCA's Vauxhall HQ, Bolt had told Mo about the night he made a pass at Tina, and about his feelings for her. It wasn't the sort of thing he usually shared; he preferred to keep matters of the heart to himself. But the drink had done what drink always does and loosened his tongue, and, with Tina having only recently departed from SOCA, he'd been at something of a low ebb. Mo hadn't approved, Bolt knew that, but he'd been sympathetic to his boss's plight, as he was now.

Bolt looked at Mo, saw the concern in his friend's eyes. He appreciated the offer but knew it was essential he didn't show weakness. 'No, it's all right,' he said. 'I'll be fine.'

One of the white-overalled officers peeled away from the throng and came over to them. 'Mo Khan?' The questioner was a woman in her mid thirties with an attractive, friendly face that didn't look like it needed much encouragement to break into a smile. Beneath the transparent hood she was wearing her hair, tied back, was a fiery red.

'That's me. And this is my boss, SG3 Mike Bolt.'

'I'm DCI Miller, the SIO on this case,' she said as the three of them shook hands. 'Thanks for coming. She's over here. The body was discovered by a dog walker approximately two and a half hours ago,' she continued as Mo and Bolt followed her to the tent. 'No real attempt to conceal the body.' She opened the flap and stood to one side. 'It looks like she was shot several times in the face and then just left where she fell.'

Bolt didn't flinch but his expression was granite as he stepped inside, barely conscious of Mo and DCI Miller filing in behind and standing either side of him.

She lay there alone, flat on her back in a halo of coagulating blood, arms neatly by her side, eyes closed. There were two small black holes in her face: one just below her mouth, the other high up on her cheek, like a large, out-of-place beauty spot. She looked asleep, peaceful, as if all the trials and tribulations of this world had been lifted from her shoulders. Which of course they had.

Bolt took a deep breath and turned to DCI Miller. 'It's not her,' he said.

I'm going to kill you.

The afternoon had turned out to be the most terrifying of Tina Boyd's life. For what must have been close to an hour she'd driven her car at gunpoint along the North Circular Road, and finally out of London on the A10 heading north. During that time the man had spent much of his time asking her questions, often touching and stroking her as he spoke. Sometimes his tone was conversational. He would ask her about her background, her likes and dislikes, her work as a police officer. Other times his tone became cruel and he'd ask her quietly, playfully, what lengths she would go to in order to live, and whether she believed in life after death.

It was clear he was enjoying tormenting her, but she'd refused to play along, answering him defiantly (she'd do what it took to stay alive and, yes, she did believe in an afterlife), yet at the same time giving him enough information to keep him interested, and even asking questions of her own, although on these he tended to be evasive. Still, she was proud of herself for remaining calm, even when they'd left the noise and traffic of the A10 behind and moved on to quieter, more isolated roads. Even when he'd ordered her to drive off one of these quieter roads and down a deserted wooded lane.

It was only when he'd told her to stop the car and taken the keys from her that the fear really hit home. Tina's legs had buckled slightly as she was ordered on to the grass verge. This was it. The moment of truth.

You've seen his face! screamed a voice inside her head. He's going to kill you!

But she hadn't panicked. Instead, she'd turned to face him, knowing that it was harder for even the most brutal killer to shoot someone in cold blood that way, forcing herself to ignore the obvious fact that she was dealing with a sociopath.

He'd raised the gun so it was pointed at her chest and they'd looked at each other for a long, lingering moment.

And then he'd smiled, and said, 'Empty your pockets, and take off your watch.'

She'd done as she'd been told, pulling out her wallet and house keys. At his command, she'd thrown them into the bushes.

He'd come forward and given her a quick one-handed pat-down to check there was nothing left behind, then opened the boot and pushed her inside, slamming it behind her.

Despite being cramped and uncomfortable, for the first time Tina had felt a real surge of hope. He intended to keep her alive, for the moment at least, and this gave her a chance.

He'd also made a mistake: he'd missed the set of picks in the back pocket of her jeans, and failed to tie her hands. She'd immediately reached round, pulled them out and shoved them into her sock where they would be even harder to locate. She knew she was taking a big risk, concealing them and risking her tormentor's wrath later, but this was a time for big risks.

The car hadn't moved, and the engine had remained off for a long time. Tina had begun to wonder if he'd simply abandoned her. Then, finally, she'd heard another car pull up next to her. She'd banged on the metal of the boot with her fist and yelled out as loudly as she could, excited at the prospect she might be freed. But when the boot opened she'd been greeted with the sight of the man with the gun again.

Without speaking, he'd pulled her out. She'd asked him what was going on but he'd told her to shut up, then shoved her roughly into the boot of the new car, a dark-coloured saloon. She'd had to push a couple of bags of grocery shopping aside before she could squeeze in, which had made her wonder where he'd got the car from. A few minutes later they were on the move again.

What was clear to Tina as she was driven along road after winding road was that the man who'd taken her was not only a sociopath but an extremely intelligent one who appeared to appreciate the tools available to the police for tracking down kidnap victims – hence his decision to get rid of her phone and her car. This was bad news, not only for her but also for Jenny Brakspear, because she was certain that this man was involved in her abduction too.

But what she couldn't understand was why he was choosing to let her live. 'Just be thankful he is, girl,' she'd whispered to herself, wondering at the same time why she'd allowed herself to end up in this position. Her desire to go it alone and bend the rules was, she'd always believed, borne out of a need to see justice done, yet there was more to it than that. There was also something self-destructive about the impulse, as if she were driven by a need to court danger, even in the knowledge that eventually she'd come unstuck.

However, now that her life truly was on the line, she realized, almost with a sense of surprise, that she desperately wanted to live. To try to return to the happier days that had been absent for far too long. Lying there frightened and hunched uncomfortably against the bags of shopping, she told herself that if she got through this she'd kick the booze – that monkey had been on her back for far too long now – and maybe even quit the force altogether and go off travelling somewhere new. South America, or southern Africa.