‘Kind of, but something more complex that could actually train the brain into remembering. Antidepressants simply mask stuff, like a magic trick, but they’re not a long-term cure. I could go into reward pathways and the dopamine highway, but I think that’s probably a bit too much.’

They all nodded.

‘Thank you for your explanation,’ Kelly said. ‘It’s been really helpful. Is it a big budget? I know the highest earner for the company is asthma drugs, but what’s the business of depression like?’

‘Controversial.’

‘Meaning?’

‘If we found a long-term cure, the money made from the short-term magic trick wouldn’t be as impressive, but that’s just my cynical opinion, and cynicism isn’t really appreciated round here. I’m sorry, it’s been an upsetting couple of days.’

‘Are you aware of George perhaps working elsewhere apart from Ravensword? Did he mention a private lab to you? What about Emily and Mike?’

The technician hesitated. ‘Actually, that’s really strange. A couple of weeks ago, Emily said something a bit odd. I was standing right behind her. They were going to play squash and then go for a meal: they regularly did that, the four of them. Emily said to George, “I’ll see you at the lab.” When I took a double take, she said it was a mistake and we laughed it off. I never thought anything of it. Were they working somewhere else?’

‘We don’t know, it’s something we have to investigate. Did George ever mention the garage he rented in Bethnal Green?’

‘No.’

‘Do you know where they played squash?’

‘I think it was Bethnal Green, because they raved about the Thai restaurant there.’

As Kelly made her way out of the lab, she googled squash clubs in Bethnal Green. As she suspected, there were none. Next she uploaded HOLMES onto her iPad; the dynamic reasoning software was accessible to anyone working the case, and she could see updates coming in live. She cross-referenced the controlled drugs residues found at the garage with what was available in George’s lab, and got a match. She put a call through to the detectives in the lab and asked if drugs used in the developmental phase could be easily stolen, or was it like in a hospital where every minute vial had to be signed for. She had a reply straight away from the technician: before drugs became manufactured in combinations they knew were safe, all lab workers had free access to them, though it would be difficult to steal large amounts and he didn’t know anyone who would.

Perhaps he didn’t know his colleagues as well as he thought.

Chapter 18