‘No sir. It’s not just you. That man is a twat of the highest order.’ She crooked her little finger. ‘I’ve heard he should be called Winklette rather than Winkler.’

Patrick couldn’t help but smile. ‘Who told you that?’

‘That would be telling. But he tried it on with me once, when I first worked here. He seemed convinced he could convert me.’

Patrick laughed, and scrolled down the screen. ‘Arrogant bastard . . . OK – let’s crack on. Don’t want to give him a second’s more head space.’

After an hour, he sat back, Winkler forgotten. ‘Right, these look like the most promising pair.’

They had identified two women. The first was called Sharon Fredericks, a 42-year-old resident of Richmond. Nine years ago, she had attempted to snatch a baby boy from a hospital, had only made it as far as the exit before she was stopped, at which point she had pulled a knife and threatened to kill both the baby and herself. A hospital porter had tackled her, getting himself stabbed in the process, but they had managed to rescue the baby without him getting hurt. At the trial, the judge had ordered Fredericks – who, it turned out, had suffered the devastating blow of SIDS twice, losing two baby boys in as many years – to be committed to a secure unit, the same one as Gill. She was released eighteen months ago. The photograph they had on file was of a pasty, hunched woman with frizzy hair, who could easily be the woman Bowie had described.

The other woman looked similar. Her name was Andrea Hertz, she lived in Teddington and, like all women in this area who were committed, she had also been in the same unit as Gill. Hertz had kidnapped her own children after custody of them was given to her ex-husband, who had convinced the court that Hertz was an alcoholic and an unfit parent. She had locked herself and the children in her car, connected a hose to the exhaust, fed it through the window and turned the engine on. Her ex had found them and smashed the car window with a brick. Andrea Hertz was still breathing, but the two children, a boy and girl, three and five years old, were both dead. This had happened twelve years ago and Hertz had been released last year.

‘Heartbreaking,’ Carmella commented.

Patrick tried not to picture the bodies of the children in the car. He said, ‘OK, Hertz is closer – let’s go talk to her first, then Fredericks.’