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.