Thomas Saunders, six years old, came out of school and was met by his young Portuguese nanny. The afternoon was fine, if a little cold and windy, but he was in a thick duffle coat that was slightly too large for him.

Holding hands, they walked to the top of the road, turned left and continued as far as a pedestrian crossing. They waited for the green man then began to cross. As they reached the middle of the road a silver Jeep Cherokee appeared. Its speed was later estimated to have been in excess of seventy miles per hour.

It never slowed down. When it hit them it was in the very middle of the road. So were they. Neil Barden, the driver, had seen neither them nor the red lights. He hadn’t seen them because, as he raced down the road, he was bending forwards, trying to snort cocaine from a small mound on his jeans, just above the knee.

The impact sent the car careering onto the kerb. It glanced off a bus stop before rebounding back into the road. At which point Barden accelerated, as if the massive physical jolt to his system had been an amazing coke rush. He accelerated. Accelerated. Right into the back of a parked Ocado delivery truck. The impact wrecked the Jeep. But the airbag saved his life.

The young nanny would need three separate operations before they moved her out of intensive care. Yet as she lay there in the road, her hand still held onto the smaller one of Thomas Saunders.

His head bore the discernible tread marks of a car tyre. The back half of his skull had been flattened so absolutely that it appeared to have been hewn from him by the swift, effective blow of a sword.

The Saunders’ marriage ended soon after, although Chris kept her ex-husband’s surname. She resigned her position as a corporate accountant, a decision which had been ‘by mutual consent’. The family home was sold. She attended the trial of the driver, then disappeared. Two years after the accident she enrolled on a teacher training course at Leeds Metropolitan University.

‘Did you read about the Barden trial, the sentencing?’ Rita asked, pressing her hands into her face.

Joe managed a sneer, the nearest he could get to an ironic smile as he felt the visceral disgust that he sometimes harboured for the whole criminal process, somewhere between loathing and a futile scream for help.

‘The report of the defence’s closing statement?’ she said. ‘I read that twice. Couldn’t believe it. Five years.’

‘Out in two.’

‘I know. I bloody read it! I know!’ A pause. ‘Sorry.’

‘Did you read the follow-up on him?’

She nodded.