‘Welcome to the madhouse,’ said Liza Hollister, the mother of the child who had seen something in Sainsbury’s car park. She was almost six feet tall, with scraped-back blonde hair and clothes straight out of the Boden catalogue.

Patrick introduced himself just as the shirtless boy of around eight dashed up and yelled, ‘Mum, Coco’s put Saskia in the toilet again.’

‘Oh for goodness sake.’ Liza stomped off and returned a few moments later with a wriggling toddler under one arm and a drenched cat under the other. She tossed the cat through the open French doors and Patrick watched it saunter off as if nothing had happened.

‘Daisy, stop banging that fucking piano,’ she shouted. She picked up a wooden spoon and banged it against a small gong that she obviously kept for such occasions.

‘Daisy, Dominic, Sebastian – go and play in the garden. And take Coco with you.’

‘Aw, mum, it’s boring,’ moaned Sebastian, the older boy who’d been playing on the console.

‘Go on the trampoline. See how high you can bounce. Go on!’ She turned to Patrick and muttered through clenched teeth. ‘Try not to land on your neck on the way down.’

The four trooped out through the French doors into the sizeable garden, followed by the three dogs, who ran around their feet and tripped the toddler over.

‘That’s better,’ Liza grinned. ‘Right, Detective Inspector. Coffee? You look like you could use one.’

‘That would be fantastic, Mrs Hollister.’

She leaned forward, giving him an eyeful of cleavage. He vaguely recognized her – then it struck him. She used to be on TV, presenting some late-night ‘yoof’ programme. She had been a ladette, always falling out of nightclubs with her knickers on display, boozing for England. She had married that rock star – what was his name? The one who played guitar in an indie band then went on to become a dance music producer.

She clattered about the kitchen making coffee – proper coffee, that she had to grind – and Patrick scanned the bookcases while he waited. There were a lot of books of erotic art. Then he noticed a photo of Liza hanging on the wall – it was her on the cover of FHM ten years before, naked, her nipples airbrushed away but her bottom on show.

Oh god, he thought. I bought that issue. He had taken it into the bathroom with him . . .

‘You alright?’ she asked, coming back with a steaming mug of coffee. ‘You look a bit hot.’

‘It is very hot in here.’

She nodded at the FHM portrait. ‘Ah, those were the days. The older kids find it terribly embarrassing having pictures of their half-naked mum hanging up, but fuck it. I was a looker in those days.’

You still are, he almost blurted. Instead, he said, ‘What do you do these days?’