I was having trouble working out why I didn’t want to drink the water. I’ve drunk water before, when beer, or coffee or Diet Coke weren’t available. I’ve drunk it from bottles, occasionally from a tap. When I was a kid I used to drink from the tap all the time. I’d run back into the flat all hot and sweaty from playing and didn’t even bother putting it in a glass, just turned the tap on and stuck my mouth underneath it. If my mum caught me doing it she used to scold me, but my dad just said that I had to be careful. ‘What if a fish jumped out?’ he used to say. ‘You’d swallow it before you knew it was there.’ Dad was always saying stuff like that and it wasn’t until I was seventeen that I realised it was because he was stoned all the time.

‘Stop that,’ I mumbled.

She gave me a pretty smile. ‘Stop what?’

I don’t mind getting drunk, but there always comes a moment in the evening when I find myself watching myself bumping into things and thinking, I’m bored of this, can I have full control of my brain back, please? I was getting equally irritated by my sudden need to deliver flowers to Hampstead and drink water from strange fountains. I tried to take a step backwards but the best I could manage was a minor shuffle.

Tyburn’s smile vanished. ‘Why don’t you have a nice drink?’ she asked.

She’d gone too far and she knew it, and she knew I knew she knew it too. Whatever influence she’d put on me must have been too subtle to handle a suggestion that obvious. Plus I’ve always wondered about that fish.

‘Good idea,’ I said. ‘There’s a pub down the road. Let’s go there.’

‘You cunning bastard,’ she said, and I didn’t think she was talking about me. She leaned in closer and stared into my eyes. ‘I know you’re thirsty,’ she said. ‘Drink the water.’

I felt my body lurch forward towards the fountain. It was involuntary, just like when you get a twitch in your leg or the hiccups, but now it was my whole body working to a purpose that wasn’t mine – it was terrifying. I realised then that the Old Man and Mama Thames hadn’t even been trying to control me and, had they wanted to, they could have had me doing cartwheels around the room. There had to be a limit to the power, or else what was to stop Mama Thames or the Old Man walking into Downing Street and dictating terms? I think people would notice if that happened – the Thames would be a lot cleaner, for a start.