The cremation suite itself stood at right angles to the chapel, with frosted windows under its square chimney stack. Inside, it had an inevitable industrial feel. The main room was dominated by two giant stainless-steel ovens with sliding doors just wide enough to take a coffin.

Cooper had only ever seen one cremator before, and that had been in Germany – a huge thing, fed by a machine built into the floor with an overhead crane to lift coffins into place, while others waited in line, as if on a conveyor belt. But the one he was looking at now was smaller. The only way of loading the coffins was by hand from a hydraulic bier.

To one side, he saw a computer control desk and a cremator operator wearing heat-resistant gloves and an aluminium apron. There was very little smell, except for the aroma of hot brick and metal from the ovens and the heat exchanger behind them.

‘Now, what would you like to know?’ said Lloyd. ‘Would it help if I began with a brief description of the way we operate?’

‘Yes, sir. For a start, does the body always stay with the coffin after it arrives here?’

‘Without exception. Our code of practice requires the coffin to be placed in the cremator exactly as received. When a coffin arrives in the committal room, it’s labelled with a card that accompanies the body right through until final disposal.’

‘How long does that process take?’

‘A modern gas-fired cremator can deal with the average body in half an hour.’

‘And the ashes?’

‘The cremains,’ corrected Lloyd. ‘Well, when they come out of the chamber, they consist mostly of bone residue. Sixty per cent of bone is nonburnable material, so at that stage there’ll be a number of bone fragments.’

Cooper was shown a cooling tray where bone residue was run under a magnet to sift out wedding rings and scraps of melted jewellery. When Lloyd lifted the lid, the cremated bones inside looked the colour and consistency of meringue – pale grey, granular and brittle. In places, their shape was still visible, but Cooper felt sure they would crumble at a touch.

They passed through into what Lloyd called the preparation room, where an electric pulverizer was used to reduce the bone fragments to ash. Now the grey material looked more like fine cat litter, the sort that Randy always refused to use.

‘From a man, we get an average weight of about seven and a half pounds of bone residue, and from a woman just under six pounds,’ said Lloyd.

‘So gender is reduced to a difference in bone structure, in the final analysis?’

‘You might put it that way, I suppose.’

Cooper filed that one away for future reference. It might be something he could point out to Diane Fry at a suitable moment.

‘Is it possible for the ashes from two different people to get mixed up, Mr Lloyd?’