‘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.

‘Do you want this coffee or not?’ I crossed the cobbles to where the angel Lesley was waiting with a polystyrene cup. ‘Anything happen while I was away?’ she asked. I sipped my coffee. The words — I just talked to a ghost who saw the whole thing — utterly failed to leave my lips.

The next day I woke up at eleven — much earlier than I wanted to. Lesley and I had been relieved at eight, and we’d trudged back to the section house and gone straight to bed. Separate beds, unfortunately.

The principal advantages of living in your station’s section house is that it is cheap, close to work and it’s not your parents’ flat. The disadvantages are that you’re sharing your accommodation with people too weakly socialised to live with normal human beings, and who habitually wear heavy boots. The weak socialisation makes opening the fridge an exciting adventure in microbiology, and the boots mean that every shift change sounds like an avalanche.