Becky could see Tom’s mind ticking over, and she stayed quiet to let him think.

‘What about the bereavement group? Did you manage to get any information from them?’

Becky sighed. ‘Yes and no. I’ve only managed to speak to the woman who runs the group, and it took a bit of persuading to get her to tell me anything. When I explained that Jasmine was dead and that we are treating her death as suspicious, she opened up a bit. She said Jasmine seemed to blame herself for Esme’s death but wouldn’t admit why she felt that way. This woman had a theory, though, based on little nuggets of information that Jasmine shared in the sessions.’

‘And that theory was…’

‘Jasmine knew how ill Esme was and had bought drugs for her sister on the street – ones she thought might lift her spirits. When Esme died, Jasmine not only blamed herself but was terrified that maybe she would be accused of killing her sister because of the drugs in her system, most of which Jasmine had acquired for her.’

‘So why would Jasmine take such a weird cocktail of drugs herself?’

‘I looked at the drug report that Lynsey wrote to see if there was any correlation – maybe Jasmine was trying the same combination as her sister to see if the drugs she procured had been the indirect cause of her death. There were overlaps but lots of discrepancies too. Lynsey was right about the pattern being weird – drugs that fire you up followed by those that calm you down. We’d ruled out any concerns about the scopolamine she’d taken, partly because she took it too long ago for it to be related to her death, but also because it’s used in legal drugs – for motion sickness, among other things. But taken in high doses it makes you lose your memory, and I don’t know if that’s relevant.’

Tom got up from behind his desk and paced the floor as if it might help him think; Becky just wished he would sit down so she didn’t have to keep swivelling her head to look at him.

‘You know it’s used a lot in South America – Colombia in particular – don’t you?’ she asked. ‘The favourite trick is to dope victims and then coerce them into emptying their bank accounts.’

Tom spun round and looked at her. ‘Devil’s Breath,’ he said, nodding. ‘It can turn you into a compliant zombie. A nasty beast and highly dangerous. It could suggest that she was being controlled. Philippa and I talked about whether she might have been involved in either the sex or drugs trade, but we have no evidence to that effect, so I’m not sure it gets us anywhere unless we can find her dealer.’