I pushed the jury-rigged power switch on my phone to the on position, gave thanks it had been off when I’d done the spell, and waited impatiently while it jingled at me cheerily and wasted my time with a hello graphic.

‘Who are you calling?’ she asked.

‘I’m calling Kittredge,’ I said. ‘Your liaison.’

‘Wait,’ she said. ‘If I explain, will you leave him out of it?’

‘No promises,’ I said. ‘Let’s find somewhere to sit down.’

We ended up, as is traditional, in a kebab shop just the other side of the bridge where I could keep an eye on my car. Although first we had to scuff about in the snow looking for Zach’s repulsive sports bag, which we finally located via its smell. Once inside I forked out for a doner and chips for Zach and a mixed shish kebab for myself. Reynolds seemed appalled by the whole notion of a rotating lamb roast and stuck with a diet coke. Maybe she was worried about contracting that insidious European E. coli. I had a coffee. Usually the coffee in kebab shops is dire but I believe the guy on the counter made me for a cop, so I got something blacker and stronger than usual. Late-night kebab shops fulfil a very particular ecological niche – that of feeding stations for people spilling out of the pubs and clubs. Since the clientele tends to be pissed young men who have utterly failed to pull that night, the staff are always pleased to have the police hanging about.

Under the harsh fluorescent light I saw that the roots of Agent Reynolds’ hair were auburn. She caught me looking and jammed her black knit hat back on her head.

‘How come you dye your hair?’ I asked.

‘It makes me less conspicuous,’ she said.

‘For undercover work?’

‘Just for everyday,’ she said. ‘I want the witnesses talking to the agent not the redhead.’

‘Why were you following me?’ I asked.

‘I wasn’t following you,’ she said. ‘I was following Mr Palmer.’

‘What have I done?’ asked Zach, but Agent Reynolds sensibly ignored him.

‘He was your best suspect,’ she said. ‘And not only did you just let him go, you let him right back into the victim’s home.’

‘I lived there too, you know,’ said Zach.

‘It was his registered address,’ I said.

‘Yes his polling address,’ said Agent Reynolds. ‘A status you can earn by filling in a single form once a year without providing any significant identification whatsoever. I’m amazed your voting security is so lax.’

‘Not as amazed as I am that Zach’s registered to vote,’ I said. ‘Who do you vote for?’

‘The Greens,’ he said.