‘Can you prove you’re dead?’ I asked.

‘Whatever you say, squire,’ said Nicholas, and stepped forward into the light.

He was transparent, the way holograms in films are transparent. Three-dimensional, definitely really there and fucking transparent. I could see right through him to the white tent the forensic team had set up to protect the area around the body.

Right, I thought, just because you’ve gone mad doesn’t mean you should stop acting like a policeman.

‘Can you tell me what you saw?’ I asked.

‘I saw the first gent, him that was murdered, walking down from James Street. Fine, high-stepping man with a military bearing, very gaily dressed in the modern fashion. What I would have considered a prime plant in my corporeal days.’ Nicholas paused to spit. Nothing reached the ground. ‘Then the second gent, him what did the murdering, he comes strolling the other way up from Henrietta Street. Not so nicely turned out, wearing them blue workman’s trousers and an oilskin like a fisherman. They passed each other just there.’ Nicholas pointed to a spot ten metres short of the church portico. ‘I reckon they know each other, ’cause they both nod but they don’t stop for a chat or nothing, which is understandable, it not being a night for loitering.’

‘So they passed each other?’ I asked, as much for the chance to catch up with my note-taking as to clarify the point. ‘And you thought they knew each other?’

‘As acquaintances,’ said Nicholas. ‘I wouldn’t say they were bosom friends, especially with what transpired next.’

I asked him what transpired next.

‘Well the second, murdering gent, he puts on a cap and a red jacket and he brings out his stick and as quietly and swiftly as a snoozer in a lodging house he comes up behind the first gent and knocks his head clean off.’