Zach had obviously thought he’d put his troubles behind him, because he’d slowed down to a fast saunter. I was nearly upon him when he glanced back, saw me and went off like a jackrabbit. He was fast, and one thing was for certain – I wasn’t about to catch him in bare feet. He’d have got away if Lesley hadn’t at that moment come out of Sainsbury’s with her shopping, seen me, seen Zach, and made the kind of lightning decision that got her voted graduate most likely to make chief superintendent by thirty at Hendon.

She didn’t try for anything flashy like a clothesline. She merely stuck out her foot and down he went on his face. Still holding two bags of shopping and my laptop, she skipped over and planted her foot on his back – holding him down until I could arrive. Between us we’d managed to attract a bit of a crowd.

‘Police,’ I said. ‘Move along. Nothing to see here.’

‘You sure about that?’ asked a voice from the crowd.

‘I’m going to let you up now, Zach,’ said Lesley. ‘Don’t do anything stupid.’

‘I won’t, I won’t,’ he said. ‘Just don’t you do anything hasty.’

‘Hasty?’ I said. ‘You just made me run naked down Tottenham Court Road. You’d rather I gave it some thought?’

A couple of uniforms turned up who neither me nor Lesley knew personally and it could have gone pear-shaped. I know I would have arrested me had I been them, except I dropped Detective Inspector Stephanopoulos’s name into the conversation and suddenly they couldn’t be more helpful. However, once you’ve invoked the name of Stephanopoulos you have to live according to her principles, unless you crave trouble, so we had to get someone from the Murder Team down to arrest Zach. While he was bundled off to an interview room at AB, I sloped back to the hospital to find my clothes and discharge myself. You’d be amazed how long that can take.

24. Sloane Square

24

Sloane Square

I was disappointed to find that there was nothing waiting for me on my desk back at the outside inquiry team office.

‘We assigned them elsewhere when you went into hospital,’ said Stephanopoulos.

Six whole days on the Murder Team and I’d only managed to fulfil about two and a half actions. Not only was it not going to look good on any performance review, but I also doubted that being engaged in a supernatural sewer battle with an underground Earthbender was going to serve as much of an explanation.

Because we wanted to avoid the lengthy booking-in process, we hadn’t charged Zach. But we made it clear that arrest and Christmas in the cells was the true alternative to ‘helping police with their inquiries’.