Fleet knew Nicky was close to her father – from what he understood, Nicky’s dad was in his seventies, and was still a practising solicitor, in spite of all Nicky’s efforts to convince him to retire. She rarely mentioned her mum, however. Until recently, Fleet had been estranged from his own mother, and although he and Nicky had bonded in an odd sort of way over their upbringings, they’d done so without ever really having talked about the details. Now, Nicky knew all about Fleet’s relationship with his mum. From the sound of it, being sent away to boarding school was at the heart of Nicky’s falling out with hers.

‘I was a mistake, essentially,’ Nicky said. ‘My mum didn’t really want children, and she’s never gone to any pains to hide the fact. Even now, on the rare occasions we speak, she talks to me the way she would an old acquaintance. Someone she’s half forgotten is still alive. And needless to say, she never asks about Dad. They were married for almost twenty years, but in her mind that counts for even less than having given birth to someone.’

Fleet didn’t know what to say. He thought of his own mother, of how grievously he’d misread the way she’d acted – but it sounded as though Nicky’s mother knew exactly what she was doing; how hurtful her behaviour would have been.

‘Parents,’ Fleet said, through a sympathetic sniff. ‘Who’d have them?’

Nicky smiled weakly. They joined the track that would take them to the chapel. The chapel itself loomed over them, the shadow of the spire like a blade across their path.

‘Six hundred pupils,’ said Nicky eventually – just for the sake of saying something, it seemed to Fleet. ‘That’s what Harris said, right?’

‘Right,’ Fleet agreed.

‘Which means … what? A hundred or so members of staff?’

Fleet thought of all the workers they’d seen in the kitchen, as well as the immaculately tended grounds. And Beaconsfield had a teaching ratio of eight to one, a detail that was plastered all over the school’s website.

‘You do realise that’s an awful lot of suspects?’ said Nicky, and Fleet couldn’t help but smile: at the obvious futility of it, mainly. Because as Nicky well knew, it wasn’t just the sheer number of suspects that they were up against. It was also the fact that most of them had scattered on the wind. After twenty-two years, and given that for most of Beaconsfield’s graduates money would have been no object, they might literally be anywhere. And anyone Fleet and Nicky could track down – potential witnesses, for example – would by default have to be considered unreliable. Most people could barely remember what they were doing twenty-two days ago, let alone a quarter of a century.