It’s early evening and dark outside. Archer has just finished briefing the team and is riled that progress is running at a snail’s pace. Patience isn’t one of her strong points, but she remains focused, knowing from experience that investigations like this can sometimes take time.

She glances at the cover of the Evening Standard left behind by one of the team. The murders are all over the front page with the exception of a smaller column devoted to the missing Tory MP, Lewis Faulkner.

‘Faulkner won’t be happy about the minimal press coverage he’s getting,’ says Archer.

‘Especially as he has been trumped by homeless people, and dead homeless people too. The indignity of it!’

Quinn has made Archer a coffee despite the fact she requested tea. She takes a sip anyway and grimaces at the bitter concoction that tastes more like liquid cigarette ash.

‘Not to your taste, then?’ asks Quinn.

She tries not to baulk and places the mug on top of the picture of smiling blond Faulkner.

Quinn sits opposite her and speaks. ‘I was thinking about this whole art thing our killer has going on and it made me think about another artist who made a name for himself a few years back. He’s a bombastic Danish man called Hornsleth or something like that who marketed himself a “conceptual artist”. Although if you replace conceptual with wanky I doubt anyone would bat an eyelid. He came to London offering cash to homeless people to take part in his project. It was a sort of human Pokémon Go.’

‘Isn’t that a computer game?’

‘Aye, it’s a Japanese game of augmented reality, so it is.’

Archer frowns. ‘What does that even mean?’

‘You’re not a gamer, then?’

Archer shakes her head.

Quinn’s face lights up for some puzzling reason. ‘OK, think of it like avatars, which are these cartoon creatures that you are able to see in the real world.’

‘OK.’

‘So Hornsleth comes to London with his photographer. Important to note that Hornsleth isn’t the photographer; he’s just an ideas man.’

‘So . . .’

‘So he scoots around London looking for homeless people that have a certain look.’

‘What sort of look?’

‘I don’t know . . . a homeless look.’

‘OK.’

‘He pays each of them a paltry sum . . .’

‘How much?’

‘I’m not sure. Two hundred quid maybe. For that money each of them has their portrait taken and he fits them with a tracking device. Hornsleth then sells his portraits online for up to £48,000 apiece. With each purchase his buyers get access to the homeless person’s tracking device so they can follow them online and track their whereabouts around London.’

‘Are you pulling my leg?’

Quinn salutes with three fingers. ‘Scout’s honour.’

‘Do you think there is a link between his art idea and our killer?’