'She's in the first room on the left,' she said wearily.

Bolt smiled, feeling sorry for her. 'Thanks. I don't see there's much I'm going to be able to do either, but I'll give it a try.'

Andrea was in the master bedroom, sitting in a white leather armchair and staring out of the bay window, a cigarette in her hand. She turned as he came inside and shut the door behind him. Her face was set hard, the tears wiped away now.

'You've got to get her back, Mike.' She spoke the words firmly.

'And we're doing absolutely everything we can to bring that about. I know how hard it must be, but you've got to try to sit tight and be patient.'

'Did you never want children, Mike?'

She watched him closely, waiting for an answer, the cigarette burning, forgotten, in her hand. He sighed, wondering how he was going to extricate himself from this conversation.

'The opportunity never arose. Maybe one day.'

'Have you ever been married?'

'I was. Once.'

'What happened?'

'She died. In a car crash. Five years ago.'

Five years. It felt like such a long time, yet in truth it had gone fast. He could still picture Mikaela perfectly, could still hear her voice. But she was someone he didn't like to be reminded of by other people. He liked to keep his thoughts and memories of her to himself.

'I'm sorry,' she said, sounding like she meant it.

'It's OK.'

Silence. He sensed there was something she wanted to add, so he waited for it.

And it came.

'Listen, Mike, I don't know how to say this, but…'

She noticed the cigarette then, and flicked the ash into an ashtray on the windowsill before it spilled into her lap.

'What is it, Andrea?'

'I told you about Jimmy Galante, didn't I? About the reason I involved him.'

'Because you needed his help.'

'Yes, and because he was her father as well.'

'That's right.'

'The thing is, I was lying.'

Bolt tensed. 'What do you mean?'

'I mean I was lying when I told Jimmy he was the father. He wasn't.'

She looked him squarely in the eye. 'You are.'

One of Mike Bolt's problems in his younger days was an inability to say no. He should never have carried on the affair with Andrea Devern after that first night of passion in the Bloomsbury hotel. She was a married woman, with a wealthy husband who looked after her, and he was an impetuous twenty-four-year-old cop, so it was always going to end in tears. But Bolt had somehow convinced himself that this didn't really matter. He was just going to see how things went and not get too involved.

But he had got involved, and in the eight weeks the affair had lasted he'd found himself driven ever deeper into Andrea's web. In the beginning he'd been in control, but that control had evaporated rapidly as he'd become more and more obsessed with her. He was driven to distraction by the difficulties in getting hold of her, and in meeting up for their illicit liaisons. In those eight weeks they slept together on only six occasions, and then suddenly it was all over. Just like that. Not with a whimper either, but with a bang he'd never forget.

But could he really have fathered her child? The thought nagged at him ferociously as he drove back to HQ. But the dates fit. Andrea had convinced him of that back at the house. 'Our daughter's birthday's the second of April,' she'd said. 'We were seeing each other in June and July.'

Our daughter. His daughter. She could be wrong, of course. As he'd found out afterwards, she was also seeing Jimmy Galante at the time. And she was married too, although she'd always claimed that her husband, Billy Devern, was impotent, which was why he'd allowed her to take lovers. Whether that was true or not was still largely immaterial, because the dates fitted. Check them, Andrea had said, and he had, going back in his head to those giddy days, and the truth shouted at him so loudly he could barely hear anything else. It was possible Emma Devern wasn't his child, but there was a damn good chance that she was.

On the seat next to him were photographs of Emma and Pat Phelan which he was taking back to the incident room. Phelan's was face up, but Emma's was face down. He couldn't bear to look at her. Couldn't bear to think that she might be his flesh and blood, and the first he'd known about it was when he'd been put in charge of investigating her kidnapping.

He thought of Mikaela, the woman he'd met a couple of years after Andrea, who'd gone on to be his wife. Mikaela had always wanted children. A boy and a girl, she'd always said. Children, and the big, rambling house with a nice garden. It was Bolt who'd always held back. He'd feared the immense commitment required; with the long hours he worked, he didn't think he could provide the necessary support. But eventually, after seven years together, he'd reluctantly agreed to Mikaela's increasingly persistent requests that they should start trying for a baby.

She was two months pregnant when the car he was driving left the road and smashed into an oak tree, crunching it into a shape that made it unrecognizable.

He'd spent six weeks in hospital and now carried three small scars on his face as a permanent reminder of that night. Mikaela's life support system was turned off three days later, without her ever regaining consciousness. Bolt had been too ill to leave his bed to say goodbye. He hadn't even been told of the decision, made by her parents, until almost two days later because it was thought the news would be so traumatic it would worsen his condition.

And all that time – all the time he'd ever been with Mikaela, and through those long hard years since – he might already have had a child. A child growing up whom he'd never seen, and knew absolutely nothing about.

His fingers tightened on the steering wheel and he clenched his jaw, feeling a sudden burst of furious resentment towards Andrea. If he was the father, why had she said nothing to him all these years? And if he wasn't, how could she manipulate him like this?

He pulled over to the side of the road before the fury got the better of him, and took some long, deep breaths, trying to calm himself down. But it was hard. Incredibly hard. That morning he'd been a reasonably happy man with a new girlfriend, coasting towards his fortieth birthday – now only a few months away – having got used to the idea that he was probably never going to have children. And now he'd been told not only that he might have one, but that her life was in terrible danger, and he was the one responsible for getting her back safely.

He sat there for a full minute, his heart thumping so loudly it felt like the only thing he could hear. Then he picked up the photo of Emma – blonde, smiling, fourteen years old, in her school uniform – and stared at it, searching for resemblances. Was she his? There were similarities, there were differences. He thought of the man – the men – holding her. The men who might not want to return her alive. The men they were now going to try to set up. For the first time, he truly imagined what could happen if their plan went wrong, and his stomach lurched violently. The girl who could be his only child would die.

He put down Emma's photo, but he kept it face up so that he could see the girl he had to rescue. It was time to take responsibility and think straight. Technically, the position hadn't changed; it was just that the stakes had now become infinitely higher.

He took a final deep breath, flicked on the indicator, and pulled out into the traffic.