‘You took sciences at A level,’ said Nightingale as we pulled out. ‘Why didn’t you take a science degree?’

‘I got distracted, sir,’ I said. ‘My grades were low and I couldn’t get on the course that I wanted.’

‘Really? What was the distraction?’ he asked. ‘Music, perhaps? Did you start a band?’

‘No sir,’ I said. ‘Nothing that interesting.’

We headed down through Trafalgar Square and took advantage of the discreet Metropolitan Police flash on the windscreen to cut through the Mall, past Bucking-ham Palace and into Victoria. I knew there were only two places we might be going; Belgravia nick, where the Murder Team had their incident room, or Westminster Mortuary where the body was stashed. I hoped it was the incident room, but of course it was the mortuary.

‘But you understand the scientific method, though?’ asked Nightingale.

‘Yes sir,’ I said, and thought, Bacon, Descartes and Newton — check. Observation, hypothesis, experiment and something else that I could look up when I got back to my laptop.

‘Good,’ said Nightingale. ‘Because I need someone with some objectivity.’

Definitely the morgue then, I thought.

Its official name is the Iain West Forensic Suite, and it represents the Home Office’s best attempt to make one of its mortuaries look as cool as the ones in American TV shows. In order to keep filthy policemen from contaminating any trace evidence on the body, there was a special viewing area with live autopsies piped in by closed-circuit television. This had the effect of reducing even the most grisly post-mortem to nothing more than a gruesome TV documentary. I was all for that but Nightingale, on the other hand, said that we needed to get close to the corpse.

‘Why?’ I asked.

‘Because there are other senses than sight,’ said Nightingale.