Bolt's team was based in an open-plan office on the fourth floor of the Glasshouse, and when he arrived about half of its dozen members were already there, drinking coffee and generally looking pretty groggy. They'd all been rousted from their beds earlier than they'd been expecting, and Bolt knew he wasn't the only one whose day off had been interrupted before it had even got going. The team had had a major drink-up two nights earlier in the West End to celebrate the arrests of the money-launderers, and it looked like one or two of his people had continued the celebration the previous night as well.

At least Mo Khan looked fairly ship-shape. Mo was one of Bolt's team leaders and the guy he trusted most. They'd been colleagues for close to five years now, first in the National Crime Squad, then at SOCA, and though, with his big round face and friendly, twinkling eyes, he bore more than a passing resemblance to a short, squat cuddly bear, the appearance was deceptive. Mo Khan was tough, efficient and unflappable under pressure, and these were three traits Bolt knew were going to come in very useful today. There was no sign yet of Tina Boyd, his other team leader, or his overall boss, SG2 Barry Freud, although Bolt knew he would be around somewhere since he was the one phoning everyone up at half past five.

He'd only just managed to say his hellos to the team members when Mo came over and collared him.

'Our mystery lady got here twenty minutes ago,' he said as Bolt poured himself a cup of strong black coffee from the percolator. 'Big Barry wants us to start the interview straight away. She's been up all night and he thinks that if we leave it much longer she's going to be too exhausted to talk.'

'Fair enough. Where is she?'

'Over in Interview Room B. Everything's set up and we're ready to go.'

'Blimey, you're quick off the mark this morning,' said Bolt, following him out the door and down the corridor. 'What time did you get in?'

'Half an hour ago. I was moving fast.'

Bolt grinned and gave him a playful punch on the arm. 'You never move fast, Mr Khan. How did you get here? Levitate?'

'I'm a man of many talents, boss.'

'So, have you seen her yet? This Mrs Devern?'

He nodded. 'I spoke to her briefly. She looks absolutely shattered, but she's very keen to talk to us.'

'I'll bet she is.'

Bolt slowed down to take a sip from his coffee, burning his lip in the process.

'Have the Hertfordshire cops checked her story out?'

'Parts of it. She's definitely got a fourteen-year-old daughter, but they haven't searched her house yet to check that she's actually missing. They're leaving that to us, in case the place is bugged.'

'So this whole thing could still be a load of bullshit?'

Mo shrugged. 'I talked to the cops who brought her in. They think that if this is all an act, then she's one hell of a good actress – but, yeah, it's possible.' He stopped outside Interview Room B. 'Guess there's only one way to find out, isn't there?'

Mo entered first, and as Bolt followed him in he experienced a lurch of shock that almost knocked him backwards. It had been a long, long time, but even looking as drawn and exhausted as she was now, with all the life sucked out of her features by whatever ordeal she'd endured these past few days, there was definitely no mistake. He knew the woman sitting in front of him.

And at one time he'd known her far too well.

Andrea Devern stood up as they came in. Mo introduced Bolt to her and they shook hands formally. Knowing that he couldn't let on that he recognized her, Bolt sat down opposite Andrea. Pleased that she made no sign of recognition either, he explained that they were only talking in such formal surroundings because their conversation could be monitored and recorded. 'This way, it'll allow us to go back over your statement more easily. But don't worry. It's not an interview under caution. We just want you to go through everything from the beginning, trying not to leave anything out, so we've got a full picture of what's happened.'

This wasn't entirely true. Given that the truth of her story had yet to be confirmed, making her repeat it would give them an opportunity to check for discrepancies later, should the need arise.

Andrea yawned, putting a hand over her mouth, and Bolt noticed that one of her manicured nails had been broken. 'I've already told everything to the detectives in Welwyn Garden City. I just want you to find my daughter.' Her tone was weary, almost irritable.

'It's important for us to hear it from you. Just in case there's anything you've forgotten. That way it'll help us to get your daughter back safely.' He gave her a reassuring smile.

'OK,' she said, meeting his eyes. 'I understand. Can I smoke in here?'

'Well, this is a non-smoking building, and Mo here has just given up a forty-a-day habit, but… What do you think, Mo?' Bolt smiled. 'Will you be able to concentrate?'

Mo didn't look too happy about it but he nodded his assent. He'd only quit the dreaded weed six weeks earlier and by his own admission was still wobbling at the precipice, but Bolt was one of those people who still believed in a common-sense approach to how the law was enforced, and it seemed churlish to deny Andrea a small pleasure at a time like this. Big Barry would probably have something to say about it, given that he usually had something to say about everything, but Bolt would worry about that later.

Andrea thanked him, removed a pack of Benson and Hedges from an expensive-looking handbag on the desk in front of her, drew out a cigarette and lit it. She took a long drag, clearly enjoying it, before blowing a thin column of blue smoke skywards. And then she started talking. As she spoke, Bolt listened carefully, taking notes, only occasionally interrupting her narrative to question her about points that needed clarification.

It's possible to tell a great deal from a person's body language about whether or not he or she is telling the truth. Liars tend to limit their physical movements, and those they do make are towards their own body rather than outwards. They touch their face, throat and mouth a lot, and will often turn their head or body away from their questioner when they talk, so that they're not facing him or her directly. Andrea exhibited none of these tendencies. Hers might have been a highly unusual story, but from Bolt's point of view she was telling the truth.

There were three reasons for this. First, she came across as genuine. Second, there was, in the end, no real point in her lying, since it would take very little time for him to verify the truth of many of her claims. And third, and perhaps most importantly, he knew her, or at least had known her once, and didn't think she was capable of a charade like this. Underneath a hard, occasionally defensive exterior, she'd always been a good hearted person.

It was why he'd once been in love with her.

Having no children of his own, Bolt couldn't begin to appreciate the extent of the ordeal Andrea was going through, but it was clearly taking a terrible toll. She was still a very attractive woman, with thick, shoulder-length auburn hair and well-defined, striking features that would make most people look twice, but today her face was haggard and puffy from lack of sleep, with dark bags under the eyes and a greyish, unhealthy tinge to the pale skin. The eyes themselves, a very light and unusual hazel that he remembered being so pretty, now appeared haunted and torn, and more than once when she looked at him as she spoke he felt an urge to reach across the table and touch her. It was an urge he fought down. There was no room for personal involvement in something like this.

'I made one mistake,' she said when she'd finished, looking at both men in turn. 'I trusted them.'