Fry paused, and looked at Cooper. He didn’t answer her, but she didn’t expect him to. He was only there for her to have someone to sound off at. Fortunately, he was good at that.

‘What’s happened, Diane?’

‘I need to talk to Brian Mullen again,’ she said. ‘He should be with his parents-in-law in Darley Dale, but they say they don’t know where he is today. And he has Luanne with him.’

‘That’s bad news.’

‘Bad news? It’s a total disaster. I’m sending Gavin out to speak to John Lowther, and to anyone else who might know where Mullen is. But I’ve a nasty feeling he’s done a runner.’

‘Are you still fancying Mullen for the arson? What would his motive have been?’

‘He and Lindsay had been having blazing rows. Loud ones, by all accounts. Their neighbour Keith Wade heard them arguing earlier that evening. The parents are being cagey on this one, so I don’t know how serious their marital problems were, but they could have been on the point of splitting up. Lindsay might have threatened to walk out on Brian, and told him he’d lose the children. That would have hit him pretty hard, I think.’

‘Oh, so he killed them?’

‘It happens, you know – some distraught dad decides to end it all, and take the family down with him.’

‘But Brian Mullen didn’t do that, did he? He was the one who survived.’

‘Well, he could have chickened out at the last minute. Once he saw the flames and felt the heat, and realized what he was doing.’

‘I suppose that’s possible.’

‘You sound doubtful. Tell me – you always seem to have some theory of your own that doesn’t fit with anyone else’s. Are you going to share it with me, Ben?’

Cooper shook his head. ‘I don’t have a theory. It’s just that …’

‘Yes?’

‘Well, if what you’re saying was really the case, I’d expect Mr Mullen to be consumed with guilt right now. He’d be thinking that he ought to have died in the fire with his family, and blaming himself for his cowardice in not going through with it.’

‘That would explain his present attitude, wouldn’t it?’

‘No, I don’t think so, Diane. It doesn’t feel right.’

But Fry had stopped listening to him. She was staring at the photograph of the Mullen family – Lindsay and the two boys, with Brian holding baby Luanne. Three of them were dead, and two still survived.

But that wasn’t the way it was running through her head. The words she couldn’t get out of her mind were slightly different, a phrase she’d learned a long time ago in the playground.

Three down, two to go.

Fry could almost hear children’s voices chanting it in the distance, their tone a mixture of triumph and challenge. They summed up the feeling of a task half done, and the determination to complete it.

Three down, two to go.

The phrase filled her with a sudden sense of urgency, a conviction that an awful disaster could be taking place right under her nose while she was distracted by irrelevant detail.

‘Ben,’ she said, ‘you know what? Right now, I bet Brian Mullen is thinking just one thing. That he ought to get on and finish the job.’

Of course, it was possible that the Lowthers were lying when they said they didn’t know where Brian was. They might only be trying to protect their son-in-law from further distress. Very admirable, but not when it got in the way of her enquiry.

Fry decided she would go straight to Darley Dale, to take the Lowthers by surprise. They wouldn’t find it easy to hide the fact that Brian and the baby were in the house if someone turned up on their doorstep.

First, she found the photograph again – the one of the whole Mullen family, Brian and Lindsay, the two boys and Luanne. This might have been one of the last pictures they had taken together. And they did look like a happy family, didn’t they? At least the Mullen children had been given a secure start in life, protected and safe, if only for a few years. It might seem the wrong way to be thinking. But there were a lot of kids who never experienced that sort of life at all, and Fry had been one of them.

There were sixty thousand children in foster care or local authority homes. It was hard for Fry to think of herself as part of a huge, anonymous mass. But that’s exactly what she’d once been – just another statistic in a depressing flow of unwanted children, shuttling to and fro through the back alleys of society; kids destined never to have a real family, or a real home.

At least for a while it had been Angie and Diane together. That had made fostering a bit more tolerable. But even that had come to an abrupt end.

Fry shut her eyes against the sudden stab of pain. It was a memory that tormented her, even now. That moment she’d realized the unbelievable: Angie had left for good, walked out of their foster home in Warley and disappeared. Ever since then, Diane had thought that she’d make things right by finding Angie. But perhaps the truth was that she had never forgiven her sister for that betrayal, and never could. It was a truth she hadn’t acknowledged until now.

Sixty thousand children. Fry knew the statistics. Half of those sixty thousand wouldn’t get a single GCSE, and would leave school with no qualifications, barely able to read or write, destined for dead-end jobs, if not a permanent place on the dole queue. Fry was one of the measly two per cent who made it to university. Many were consigned to a life on the street, holed up in a filthy squat or crack house, pissing away their existence. Some care-home children felt unwanted and unvalued for the whole of their lives. Many never formed a normal relationship, because they didn’t know how. They’d never been shown.

Two thirds of those children were in care because they’d already suffered abuse or neglect. One in eight moved foster homes more than once a year. And that was a problem, when there was already a shortfall of foster carers. Too many kids, and not enough places for them to go. Fostering was a tough job. Now she’d heard that the government was considering putting vulnerable children in boarding schools and paying their fees.

Fry turned back to the photograph of the Mullen family. But it wasn’t Lindsay Mullen and the two boys she was looking at now. They were dead, and past saving. Her focus had shifted.

She held the print up to the light from the window, trying to bring out the depth of colour that suddenly seemed so important. She was studying Brian Mullen and the carefully wrapped bundle in his arms. Luanne Mullen, aged about twelve months at the time the photo was taken. It was unusual, perhaps, for a child of that age to be held by the father in a family group. She might have expected Lindsay to be the one showing off the baby, with the father proudly flanked by his two sons. But that wasn’t the way the Mullens had posed.

That detail might have been what drew Fry’s attention. It was like a tiny fly twitching its wings in the ointment, a flaw in the normal expectations. Insignificant in itself, but still …

As she stared at the child’s face, Fry suddenly realized how extraordinarily beautiful Luanne Mullen was. She wasn’t the type to fall into a gooey heap every time she saw some unprepossessing infant with jowls like Winston Churchill. Not at all. Most babies were ugly as sin, except to the poor benighted parents, who couldn’t see the reality in front of them because their eyes were glued shut with bewilderment and exhaustion. But not Luanne. Churchill had never looked like this. In fact, Luanne Mullen was the most beautiful child she’d ever seen.

Then Fry was struck by the contrast between Luanne and her father. Not that Brian was repulsive, exactly, but he was fair-haired, angular and pale. Luanne, on the other hand, had black hair – so black that it was startling in a child of her age. Her eyes were dark, too, like little pools of black ink.

And there was another thing – the child’s skin was surely several shades more Mediterranean than Brian’s English pallor. So what about the mother? Well, there she was – blonde hair, showing light brown at the roots. And green eyes.