Bolt burned with the intense frustration any police officer feels when a criminal he or she knows is guilty gets off through lack of evidence; the fact that he'd shot one of Bolt's colleagues made it almost unbearable. But bear it he had to, and shortly afterwards Galante disappeared off the scene, moving to Spain, away from the watchful eyes of a vengeful Flying Squad.

Bolt had never heard from Andrea again after that. He'd tried to make contact with her several times but she hadn't returned his calls, and he'd been forced to accept that their relationship was over. But for him, personally, it had been a coup. His information had led to a huge result for the Flying Squad, marred only by wounding and injury to two of their own, and the fact that he'd shot dead one of the gang only increased his kudos among his colleagues. There'd been no repercussions from the PCC – his shooting of Hayes was considered totally justified – and although he'd been asked on several occasions to name the source who'd told him about the robbery, he'd always claimed that it was an informant, and gave no further details. Because the op had been a success, no one had ever pushed him on it.

He continued to pace the room. Continued to think. Always about Andrea. How her information had foiled a major robbery and put a lot of very nasty people out of business, at least one permanently. How she seemed to have turned her life around so formidably in the years since. And how she could have made some serious enemies along the way.

He stopped pacing and put down his wine on the marble kitchen top. He had an idea, and for the first time in the last few hours he felt a twinge of hope, coupled with something approaching excitement.

Pulling the mobile from his pocket, he dialled a number he hadn't called in far too long.

Emma dug away in the gloom with the rusty nail, trying to shut the constant fear out of her mind, forcing herself to concentrate totally on what she was doing. It had been dark for over an hour now but still she kept going, even though every part of her body seemed to ache with the effort. It was a slow, painful job, but she was getting somewhere. She'd created a gap of almost a quarter of an inch between the wall and the plate on the left-hand side, enough almost to get a finger underneath, and when she tugged at the chain it definitely felt looser. If she could just keep at it, eventually it was going to come free. She was sure of it. But God, it was hard.

She heard a noise upstairs – footsteps. She froze. If they saw what she was doing, they'd punish her. The cruel one might even decide that keeping her alive was now too risky, that it was time to get rid of her altogether.

She jumped up, lifted the bed, straining with the effort, and pushed it back against the wall, trying to be as quiet as possible but unable to stop it from scraping loudly on the stone floor.

Please don't let them hear it.

Gritting her teeth, she lay back on the bed, put the nail under her pillow, and reached for the hood.

The footsteps stopped. Was one of them outside the door?

She put on the hood and closed her eyes, hardly daring to breathe, terrified that this might be it. The last few seconds of her life. Had all her efforts of the last few hours been wasted?

But the door didn't open.

Five minutes passed. Then ten.

She lay there in the darkness, her heart going faster and faster, cold beads of sweat running down her forehead as she listened as hard as she could for any sound in the room, knowing that the cruel one always liked to creep up on her.

But she could hear nothing. Only silence. And eventually she plucked up the courage to remove the hood and look around. But the room was empty.

So, he wasn't coming for her tonight.

But she couldn't help thinking it was just a stay of execution.

In the old days, everyone in the Flying Squad had had a nickname. Bolt's, not altogether surprisingly, was Nuts, while Jack Doyle, the man he was going to meet, had been known as Dodger. Although he was five years older, Doyle had probably been Bolt's best mate in the squad. He was also the most accident-prone guy Bolt had ever known.

Doyle's long litany of injuries was legendary: three months in traction after falling off a ladder trying to retrieve a football from his roof; a rare and potentially deadly blood infection when he'd stepped on a fishbone on the first day of his honeymoon; and in the most bizarre instance of all, a month off sick with concussion after a pool tournament during which a wildly mishit cueball flew off the table, hit him in the temple and knocked him spark out. Somehow his injuries always coincided with times when the squad were in action, hence the nickname, and it irritated him hugely because he'd always been one of its hardest members, and as a highly successful former amateur boxer was not afraid of a fight. He simply considered himself unlucky.

Jack (Bolt had never called him Dodger) was one of the few of the old team still left at Finchley. He'd moved up the ranks and was now a DI. His experience, coupled with a near photographic memory, meant that if there was ever anyone who could provide Bolt with the information he needed, it was him. Although they'd kept in touch over the years, and still did the occasional fishing weekend away, it had been months since they'd last spoken. Even so, as soon as Bolt explained that he needed to meet up with him urgently, Doyle hadn't hesitated, and told him to name the time and place.

And so it was that barely an hour after arriving home Bolt walked in through the door of the King's Arms, a busy, old-fashioned drinkers' pub just off the King's Cross end of the Gray's Inn Road. He had to look around for a few seconds, pushing his way through the buzzing crowd of drinkers, before he saw Doyle sitting in a booth in the corner, two pints of lager set out on the table in front of him.

Doyle stood up as Bolt approached and they shook hands. As always, the other man's grip was vice-like. With his jutting, granite jaw and square shaped head, topped with thick black hair, Jack Doyle bore a strong resemblance to a Thunderbirds puppet – not that it was advisable to tell him that. He wasn't a particularly big man – no more than five nine, and of slim build – but the look was deceptive. He was all sinewy muscle, and even now, in his mid-forties, there wasn't an ounce of fat on him.

'How are you, Mike?' he asked in a thick Glasgow accent that hadn't mellowed, even after more than a quarter of a century down south. He gestured at one of the pints. 'I got you one in.'

Bolt smiled as they sat down opposite each other.

'Thanks, Jack, I'm all right,' he said, determined not to show the turmoil he was going through. 'You?'

'Not bad,' said the other man wearily. 'Counting the days until retirement.'

They clinked glasses.

'What is it you've got left now? Five years?'

'Four. And I tell you, pal, I can't bloody wait. How's life at SOCA?'

Bolt took a gulp of his beer. It tasted good.

'Busy,' he answered. 'That's why I need your help. You remember the Lewisham robbery, back in ninety-two? The police van carrying the coke for incineration?'

'How could I forget? It's the one where you made your spurs. Took out that toe rag Dean Hayes.'

Bolt nodded. 'That's the one.' He'd never been proud of the fact that he'd killed Hayes. He might have been, as Doyle put it, a toe rag, but that didn't make ending his life any easier, and Bolt felt mildly uncomfortable at it being mentioned now. 'Do you remember what happened to the people who got put away for it?'

'Is this to do with a case you're working on?'

He knew there was no point denying it. 'Yeah, it is.'