‘It’s a he,’ said Abigail. ‘He’s up at the school.’

‘Come on then,’ I said.

‘What, now?’ she said. ‘But it’s freezing.’

‘We know,’ I said. It was one of those dull grey winter days with the sort of sinister cold wind that keeps on finding ways through the gaps in your clothes. ‘You coming or not?’

She gave me the patented stare of the belligerent thirteen-year-old but I wasn’t her mother or a teacher. I didn’t want her to do something, I wanted to go home and watch the football.

‘Suit yourself,’ I said and turned away.

‘Wait up,’ she said. ‘I’m coming.’

I turned back in time for the door to be slammed in my face.

‘She didn’t invite us in,’ said Lesley. Not being invited in is one of the boxes on the ‘suspicious behaviour’ bingo form that every copper carries around in their head along with ‘stupidly overpowerful dog’ and being too fast to supply an alibi. Fill all the boxes and you too could win an all-expenses-paid visit to your local police station.

‘It’s Sunday morning,’ I said. ‘Her dad’s probably still in bed.’

We decided to wait for Abigail downstairs in the car where we passed the time by rooting through the various stake-out supply bags that had accumulated over the year. We found a whole tube of fruit pastels and Lesley had just made me look away so she could lift her mask to eat one when Abigail tapped on the window.

Abigail, like me, had inherited her hair from the ‘wrong’ parent but, being a boy, mine just got shaved down to fuzz while Abigail’s dad used to troop her over to a succession of hair salons, relatives and enthusiastic neighbours in an attempt to get it under control. Right from the start Abigail used to moan and fidget as her hair was relaxed or braided or thermally reconditioned but her dad was determined that his child wasn’t going to embarrass him in public. That all stopped when Abigail turned eleven and calmly announced that she had ChildLine on speed-dial and the next person who came near her with a hair extension, chemical straightener or, god forbid, a hot comb was going to end up explaining their actions to Social Services. Since then she wore her growing afro pulled into a puffball at the back of her head. It was too big to fit into the hood of her pink winter jacket so she wore an outsized Rasta cap that made her look like a racist stereotype from the 1970s. My mum says that Abigail’s hair is a shameful scandal but I couldn’t help noticing that her hat was keeping the drizzle off her face.

‘What happened to the Jag?’ asked Abigail when I let her in the back.