Nodding her head to the music, she tipped out the powder; measured and scraped and cut. She rolled up the note and stared at the lines, at the flyaway grains that dotted the tabletop around their edges. Insubstantial. Virtually weightless.

Something so wonderful coming from nothing.

Fifteen minutes from the Mullen house, in the largely affluent suburb of Stanmore, Butler’s Hall School had occupied its hundred-plus acres of lush parkland for a little under a century.

Holland read a potted history of the place, flicking through the school’s lavish prospectus as he waited in a car at the end of a mile-long driveway. Of its 250-plus pupils – most of whom were fed in from a nearby prep school in the same foundation – almost a third were boarders. Of the total number, around 40 per cent were girls, first admitted as sixth-formers in the early eighties, then into the main body of the school ten years after that.

Kenny Parsons, who had gone in search of a toilet fifteen minutes earlier, knocked on the window. Holland looked up, wound down the window.

‘It’s a fair bet that if you can afford to send your kids here, you can afford to cough up a decent ransom,’ Parsons said. ‘These kids might as well have targets on their backs.’

‘Wouldn’t be allowed,’ Holland said, lifting the brochure. ‘There’s a very strict uniform code.’

Parsons looked back towards the school. ‘There’s a very strict everything code.’

Holland got out of the car, tossed the brochure on to the back seat. He and Parsons began walking towards the school building. ‘“Falsehood dishonours me”,’ he said.

‘Come again?’

‘That’s the translation from the Latin, apparently. “Lies shame me”, or whatever. The school motto.’

Parsons nodded, vacant. ‘The lower sixth should be out in a minute,’ he said.

The end of the school day was staggered, with pupils from upper and lower years coming out at twenty-minute intervals. Porter and three colleagues, working in teams of two, were already elsewhere on the school premises, talking to children from the fourth and fifth forms in the presence of teachers or parents. As Holland and Parsons moved towards the school’s main exit, they joined another pair of SO7 officers, falling in behind them as they walked across the car park, cutting through the massed ranks of silver or black people carriers: Porsche Cayennes, Volvos and BMW X5s. One of the officers, a skinny Essex boy with bad skin, put his face close to the tinted window of a Lexus as he passed, tried to see inside. ‘What do these people do?’ he said.

Holland, Parsons and the others stopped in the school quad, loitering outside a pair of vast wooden doors, which slammed open as the first of the students began to emerge. Like all those officers working on site, the four were smartly, though informally, dressed: khakis and casual jackets; suits over polo shirts. They could easily have been teachers, or even, in one or two cases, students out of uniform.

Parsons was clearly still thinking about his colleague’s question as he watched the first wave of pupils emerge, and spoke above their chatter. ‘Well, I don’t think many of them are coppers. And I can’t see any of their kids becoming coppers, either.’

‘They do have scholarship places,’ Holland said. ‘Not everyone’s dad’s an oil billionaire or a footballer, you know.’

‘That’s a fair point,’ the Essex boy said. ‘Take Mullen for a kick-off. Unless he was seriously bent, I can’t see how he’d be rolling in it.’

Parsons said something about a DCI’s pension, about Mullen making seriously good money as a security consultant, but Holland had stopped listening. He was watching two girls, aged fifteen or so, heads together, whispering. He was thinking about Chloe. Deciding that, even though it was a long way off, he wouldn’t argue if there was so much as a chance of her getting into a place like this. That he would argue until his last breath with the idea of her ever becoming a copper.

Officers had travelled to Butler’s Hall late on the Monday – the first day the unit had become involved – and taken more statements the day after that, but it was understandable that Barry Hignett was keen to speak to everyone who might have anything to add. Understandable in that, until the people holding Luke Mullen decided to let the police or his parents know exactly what they wanted, there was little else that could usefully be done.

Pupils had been spoken to in school. They were told that Luke Mullen was still missing and that there would be police officers waiting to talk to them if they felt they had anything useful to report. The headmaster had been at pains to remind them that neglecting to do so would be as good as falsehood, and every bit as dishonourable. They were urged to pass on any information they had, however trivial it might seem, about the Friday afternoon when Luke had been driven away.

The Essex boy and his partner paired off, taking up a position at the other end of the quad, but neither they nor Holland and Parsons were exactly swamped by the rush of eager young informants.

Those few pupils Holland and Parsons did speak to all told just about the same story. It became clear that over the previous few days the school jungle drums had been working overtime and that it would not be easy to sort out the fact from the hearsay.

One boy assured Holland that Luke Mullen had run off with a sexy older woman. Several sixth-form girls swore blind that they’d seen Luke and the mystery woman kissing two or three days earlier. One of Luke’s classmates said that he thought Luke had a secret girlfriend; that he’d been dropping hints about going away somewhere with her. Spain, maybe, or France.

Nothing they were told took them any closer to identifying the car. It was still probably a Passat, and more likely dark blue than black, but the partial number plate had now become all but useless, with another dozen different letters and numbers passed on by those who swore they’d seen it drive away with Luke Mullen inside.

The descriptions they were given of the woman were much the same as they already had, though, again, such statements became less credible once it became clear that those giving them had been talking to each other. She was in her late twenties. She was dirty blonde. She was very skinny. ‘Tasty, though,’ one of Luke’s classmates had said. ‘Luke reckoned she was fit. Mind you, he hadn’t got much to compare her to, had he?’

The emphasis in this, as in all similar dealings with the public, was on the search for a missing teenager. It was certainly not talked of as an abduction; and, in line with standard practice, the word ‘kidnap’ was never used by officers outside of Central 3000 or the Mullen house.

A school, however, was as perfect a breeding ground for conjecture as it was for stomach bugs or cold sores.

‘This woman’s the one who kidnapped Mullen, yes?’ The boy was fifteen, a year below Luke, but his manner was that of a pupil three or four years older.

‘I can’t go into too many details, I’m afraid,’ Holland said. The boy had neatly parted hair and was carrying a small briefcase. Holland guessed that he was probably not a big star on the rugby field.

‘I understand.’

Holland saw straight away that it was best to speak to the boy as if he were genuinely as mature as he appeared. ‘But she’s certainly someone we’re interested in tracing.’

‘How much of a description do you have?’ the boy asked.

Holland exchanged a look with Kenny Parsons, then gave the boy the basic facts. ‘Obviously, if there’s anything more you can add…’

‘I’m doing S-level art,’ the boy said. ‘I’m one of the best in the year.’

Holland stared at him.

‘I got a pretty good look at the woman with Luke. I could probably draw her, if you’d like.’