‘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.’

‘You’re having me on,’ I said.

‘No I’m never,’ said Nicholas, and crossed himself. ‘I swear on my own death, and that’s as solemn a swear as a poor shade can give. It was a terrible sight. Off came his head and up went the blood.’

‘What did the killer do?’

‘Well, having done his business he was off, went down New Row like a lurcher on the commons,’ said Nicholas.

I was thinking that New Row took you down to Charing Cross Road, an ideal place to catch a taxi or a minicab or even a night bus if the timing was right. The killer could have cleared central London in less than fifteen minutes.

‘That wasn’t the worst of it,’ said Nicholas, obviously unwilling to let his audience get distracted. ‘There was something uncanny about the killing gent.’

‘Uncanny?’ I asked. ‘You’re a ghost.’

‘Spirit I may be,’ said Nicholas. ‘But that just means I know uncanny when I see it.’

‘And what did you see?’

‘The killing gentleman didn’t just change his hat and coat, he changed his face,’ said Nicholas. ‘Now tell me that ain’t uncanny.’

Someone called my name. Lesley was back with the coffees.

Nicholas vanished while I wasn’t looking.

I stood staring like an idiot for a moment until Lesley called again.