A white boy with dreads lurched into my little corner of the train and I caught a whiff of patchouli, tobacco and marijuana. The woman in the halter top hesitated and then moved closer to me – apparently I was the lesser of two evils.

‘The dogs, the dogs,’ shouted the ranting drunk from somewhere down the other end of the carriage. ‘This country is going to the dogs.’ The happy train lurched into movement again.

Revenants had to be rare or there’d be no ghosts left for them to feed on, which brought me back to my question: what made a revenant? Psychological state at the moment of death, maybe? Henry Pyke had died a pointless and unjust death even by the lax standards of the eighteenth century but even so, his resentment at Charles Macklin and burning disappointment at the sad state of his acting career didn’t seem enough motivation to make him want to force poor Bernard Coopertown to beat his wife to death.

‘Used to be a fucking paradise,’ shouted the ranting drunk. He couldn’t be talking about Camden Town which, despite the markets, had never really aspired to much more than shabby respectability.

Camden tube station is where the Northern Line splits into the Edgware and High Barnet branches, and here loads of people got off and even more people got on. We all crushed up a bit more and I found myself staring at the top of the woman in the halter top’s head – she had blonde roots and dandruff. The man in the blue blazer got shoved in from the right, and between them they had me boxed against the door. We all shuffled about trying to keep our armpits out of each other’s faces – just because it’s uncomfortable, there’s really no excuse for not maintaining standards or making eye contact.

The ranting drunk welcomed everyone aboard. ‘The more the merrier,’ he said. ‘Let’s have the whole fucking world in here – why not?’

The smell of the white boy with dreads intensified, adding urine and excrement – I wondered when he’d last changed his fake combat trousers.

Less than a minute out of Camden Town, the train lurched to a stop. An almost subliminal groan rose from the passengers, especially when the lights dimmed as well. I heard someone chuckling at the other end of the carriage.

There had to be something else behind Henry Pyke, I thought, something much worse than a bitter failed actor.

‘Of course there is,’ shouted the ranting drunk. ‘That would be me.’

I craned my neck to spot the drunk, but my view was blocked by the white boy with dreads whose face now had an expression of dumb satisfaction. The smell of shit got worse, and I realised the boy had just relieved himself in his pants. He caught my eye and gave me a big smile of contentment.