Adrian Harris was surprised to see him. All the more so when Fleet, on stepping into Harris’s office, reminded him of the offer he’d made the first time the two of them had met. But the headmaster recovered himself quickly, and rose rather stiffly from his leather chair, before escorting Fleet to the library himself.

‘Is it just the fire you are interested in reading about, Detective Inspector?’ There was a curiosity in the headmaster’s tone that went deeper than a desire for an answer to his question.

‘For the time being, I think. Thank you, Mr Harris. I recalled you mentioning you had some literature available on the subject.’

The headmaster showed Fleet to a table right in the centre of the room. There were no children around. It was mid-morning, and Fleet presumed they must all be in lessons. Other than Fleet and the headmaster, the only other person in the library was the librarian, a short, frail-looking woman with a stare that was several degrees chillier than the room itself.

The headmaster’s leather soles resounded on the parquet floor as he perused the stacks. It didn’t take him long to find what he was looking for, and by the time he’d returned to the desk, he already had the book spread open to the relevant pages. He set the volume on the table, and Fleet found himself looking at an image that reminded him of a Turner painting of the burning of the Houses of Parliament. Art wasn’t ordinarily Fleet’s thing, but in the past Holly had dragged him around various exhibitions, and once in a while a painting would strike a chord. Turner’s images of London aflame had been among them: the vicious swirl of the reds and oranges; the white so intense you could feel the heat. According to the caption in the book, there were no surviving photographs of the fire at Beaconsfield, and the painting had come to represent the most famous recorded image of the event. It was beguiling enough even to Fleet’s eyes. What would a teenager have made of it, he wondered? Especially if they’d hated the school as much as Callum Richardson claimed Melissa and Lance had.

‘Is there anything else I can help you with, Detective Inspector?’

Fleet flicked a few pages ahead, and saw that the story of the fire was narrated over an entire chapter. The volume itself was the size of one of Holly’s cookery books. A History of Beaconsfield College, read the title at the top of the page.

‘No, thank you, Mr Harris. This will be ample.’

‘Very well, then. You may leave the book with Ms Cole, our librarian, when you are finished. She will ensure it is returned to the shelves in the correct place.’