Lockhart prints out some papers from the computer, adds them to the small pile on the side of his desk, then opens the top drawer on the left-hand side. It contains his handcuffs in dull black metal, a canister of CS spray in its holster and a half-eaten chocolate-covered flapjack. He takes out the flapjack. It’s hot in the office, Victorian heating pipes on full, non-adjustable. The chocolate coating sticks to the plastic wrapper and comes away as he unwraps the flapjack: he frowns, takes a bite. The flapjack disintegrates all over him but he doesn’t notice as he is too busy using his front teeth to scrape the chocolate away from the plastic wrapper when Barker comes in, the door to the office swinging open so swiftly that Lockhart is caught with chocolate on his teeth and oats on his shirt.

‘Ugh,’ says Barker, ‘how come you eat so much of that crap?’

‘Sir,’ says Lockhart, swallowing.

‘Why don’t you go over and get a pasty for God’s sake, they’re much more healthy for you. I hope your mother raised you to brush your teeth regularly.’ Barker stops where he stands and his expression takes on a philosophical air. ‘When you think about it, all we really are is teeth.’

Lockhart gives Barker a querying look.

‘Yes, think about it, son,’ Barker says, warming to his topic. ‘DNA doesn’t count because that’s everything, and invisible, it’s just science, and I know there’s fingerprints but think how quickly they go – decomposition I mean.’ Lockhart has an image of insects, many types of insect but blowflies mostly, hiding in eyes and mouths and nostrils. Thanks for that, sir, he thinks. ‘So discounting fingerprints,’ Barker continues, ‘it’s really all about teeth.’ Barker bares his own teeth in a grin that has only a fleeting relationship with mirth. ‘Show me yours.’

‘Sir?’

‘Show me your teeth.’

Lockhart runs his tongue over his teeth and pushes his lips letterbox-shaped.

‘Thought so,’ says Barker. ‘They aren’t any whiter than mine, it’s just the skin contrast. You’re lucky, you know, you lot, must save you money on cosmetic dentistry.’

Lockhart wants to say, that will be You Lot with a capital Y and a capital L then, meaning all Asian or part-Asian people all over the world who regardless of age, class or geographical location all have the same characteristic because we just do. He does not share this thought with his boss. Instead he says mildly, ‘I must admit I’ve never thought of it that way, sir.’

Barker claps his hand on Lockhart’s shoulder. ‘Stick with me, son, you’ll learn a whole load of things you’ve never thought of.’ He is sort of taking the mickey out of himself at this point. ‘How’s the report coming along?’