The first rule about a black woman’s hair is you don’t talk about a black woman’s hair. And the second rule is you don’t ever touch a black woman’s hair without getting written permission first.

If you ask any police officer what the worst part of the job is, they will always say breaking bad news to relatives, but this is not the truth. The worst part is staying in the room after you've broken the news, so that you're forced to be there when someone's life disintegrates around them. Some people say it doesn't bother them - such people are not to be trusted.

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.

...good-Samaritanism in London is considered an extreme sport - like base-jumping or crocodile-wrestling.

...don't ask me why I know what an Edwardian smoking jacket looks like: let's just say it has something to do with Doctor Who and leave it at that.

You put a spell on the dog," I said as we left the house. "Just a small one," said Nightingale. "So magic is real," I said. "Which makes you a...what?" "A wizard." "Like Harry Potter?" Nightingale sighed. "No," he said. "Not like Harry Potter." "In what way?" "I'm not a fictional character," said Nightingale.

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.