‘Much like the rest of us, yes.’ Bloom replaced the red pen in its tray. ‘They live their lives the best they can. Some know they are different and hide it, some simply believe they’re normal and assume other people think and feel the way they do.’

‘I’d say those last characteristics, the ones in red, are the real traits of a psychopath. And you haven’t seen any evidence of any of those in our four players,’ said DI Carly Mathers.

Chief Superintendent Barker answered for Bloom. ‘Because those are much harder to observe. They’re about how that person feels: a lack of guilt, a lack of empathy, a big ego.’

‘Exactly,’ said Bloom. ‘We can’t judge those things without speaking to the individuals themselves.’

DS Green was nodding but the scowl remained. ‘So let’s say all four are psychos. Why the hell would they play a stupid game?’

‘People who possess these antisocial traits experience emotions less keenly than the rest of us. They rarely feel scared, coerced, or motivated to fit in, and so their decisions are calculated on the basis of What do I gain? Life is a game to them. They’re often highly competitive, feel superior to their fellow human beings, and make decisions from a totally selfish position.’

‘So a game would appeal to them more than it would to a normal person?’ said DC Kaye Willis.

Bloom chose not to challenge the concept that there is any such thing as a normal person. ‘More than that. If I’m right, this game has been designed specifically for them. I think someone has selected people with these traits and invited them to play.’

‘Selected how?’ Barker asked.

‘I don’t know. That’s where I need your help.’ Bloom looked at DC Logan. ‘Could it be something online? Somehow tracking their decisions and behaviours? Or even getting them to complete a questionnaire?’

‘How the hell do you do that without people getting suspicious?’ DS Green said.

‘People are completing questionnaires all the time,’ replied DC Logan. ‘For marketing purposes. All those pop quizzes. “What type of animal are you?” Things that trend on social media. They’re all designed to collect our personal data.’

‘So someone could place their own questionnaire into the mix to identify psychopaths?’ Jameson seemed to be coming around to the theory.

‘It’s possible. I can look at the online activity of these four people and see if they completed any quizzes or questionnaires,’ said Logan.

‘Perfect,’ said Bloom.

‘And how sure are you of this theory?’ said Chief Superintendent Barker. ‘How much effort should we be putting into this theory compared to the other two?’