I had never in fact visited a real crime scene, but had seen many photographs and reconstructions. Of course I had written about them. It was always tempting to over-describe the chaos and horror of the aftermath of a murder. I had succumbed to that temptation when I was writing my early books. Spilled blood and dismemberment, dropped weapons, cartridge cases, blood-covered knives, deadly clues, all these were interesting to write about and brought a sense of visual excitement to a story.

Thrillers are for much of the time internalized: the characters wonder and speculate, hide secrets, worry about what will happen next, form suspicions. The sleuth theorizes about motives and methods, calculates who was where and when, notices accidental revelations of clues, carries out interviews with recalcitrant witnesses, obsesses over railway timetables. Thrillers are not especially thrilling.

‘On this occasion I understand the crime scene has been preserved, almost exactly as it was discovered,’ Spoder was saying. ‘Whatever mess there was has been cleaned up long ago, of course. But the place, the scene of the murder, is as it was on the day. I assure you this is a truly unusual and astonishing story. I am indebted to you for bringing me in on it. All will become clear as soon as we reach Sekonda.’

‘Spoder, if you go to Sekonda you go without me.’

He took one of my bread rolls, split it in half and smeared some fruit preserve across it. He took a huge mouthful. Then he licked his long fingers and ferreted around inside the file. He pulled out what looked like two pieces of card. He slapped them down on the table and covered them with his free hand before I could pick them up.

‘Here is the proof of twin brotherhood you have secretly been worrying about,’ Spoder said. ‘This is a photograph of Lew Antterland, taken in the same year he died.’

He turned over the first picture. I had not formed any kind of mental image of the dead man, so the head and shoulders photograph that Spoder now showed me was a revelation. Lew Antterland was a young man, in his mid-twenties. He had a rather square face with noticeable jowls, pale blue eyes spaced well and with a direct look. His short hair was combed forward. He was clean-shaven. His face was unlined.

‘Now look at Dever. This was taken about five years later. Again, I think this must have been not long before he died.’