What frustrated me was the thought that with three thousand years of history someone in China, some monk in a monastery halfway up a mountain, must have developed a magic kata, a physical expression of formae. Or at least have got close enough to explain all those legendary swordsmen and their inexplicable desire to roost on the tops of bamboo trees.

Not being invited in is one of the boxes on the “suspicious behavior” bingo form that every copper carries around in their head along with “stupidly overpowerful dog” and being too quick to supply an alibi. Fill all the boxes and you too could win an all-­expenses-paid visit to your local police station.

Conflict resolution,' said Nightingale. 'Is this what they teach at Hendon these days?' 'Yes, sir,' I said. 'But don't worry, they also teach us how to beat people with phone books and the ten best ways to plant evidence.

Despite my mum being from a small village in the middle of a forest, I'm not a country person. I don't like my bacon sandwich to be curiously snuffling at my fingers. But sometimes being police means holding your breath and fondling a pig.

What's the biggest thing you've zapped with a fireball?' I asked. 'That would be a tiger,'said Nightingale. 'Well don't tell Greenpeace,' I said. 'They're an endagered species.' 'Not that sort of tiger,' said Nightingale. 'A Panzer-kampfwagen sechs Ausf E.' I stared at him. 'You knocked out a Tiger tank with a fireball?' 'Actually I knocked out two,' said Nightingale. 'I have to admit that the first one took three shots, one to disable the tracks, one through the driver's eye slot and one down the commander's hatch - brewed up rather nicely.

My Dad says that being a Londoner has nothing to do with where you're born. He says that there are people who get off a jumbo jet at Heathrow, go through immigration waving any kind of passport, hop on the tube and by the time the train's pulled into Piccadilly Circus they've become a Londoner.

My dad was a fairy," said Zach. "And by that I don't mean he dressed well and enjoyed musical theatre.