‘I’m just saying that if you felt that underneath everything, you were a boy, that is a conversation we could have.’

Indigo gave a laboured and heavy sigh. ‘I know it was always a disappointment to you, but I was born with a vagina. I’m eleven, so I don’t really know what I’m supposed to do with it yet. But now you want me to swap it?’

‘No, of course not.’ This really wasn’t going well.

Another sigh. ‘I don’t know what you want me to be, Mum. Maybe you should wait until you figure out who you are.’

Disturbing the chief constable on a Sunday afternoon was never something to be done lightly, but Gillard knew he would get a fair hearing. Alison Rigby answered on the third ring.

‘Yes, Craig?’

‘Huge progress ma’am,’ he said. ‘As you will have read, Mrs Roy had been exposed to thallium over the last few months. We were struggling to find out exactly how. We tested every item of food in her kitchen in Richmond as well as in the flat in Leatherhead, and all her toiletries. Nothing reacted to the tests. However, DI Mulholland on her own initiative visited Mrs Roy’s office and found some toiletries there in a drawer. It turns out that someone had injected a roll-on deodorant with the poison. I can only presume that the reason she is still alive is that she didn’t use this deodorant every day, just occasionally.’

‘Do you have a suspect?’

‘Not yet, ma’am. I need to speak to Mulholland, but I’m sure we will be narrowing it down. I just wanted to let you know this stage because—’

‘Because this couldn’t be Jason Waddington, right?’

‘Correct, ma’am. We’ll need a few more hours to narrow down who could possibly have done this, who might have had access to her office.’

‘Thank you, Craig. We still have something of a conundrum, though, don’t we? The actual murder was a crude assault undertaken by a male on a bicycle. Someone who would have known that she was likely to be walking her dog on Ashtead Common very early on a Sunday morning. If we are assuming that the earlier poisoning was undertaken by the same person, the same man, he would presumably have been frustrated that he had not managed to kill her.’

‘My thoughts exactly, ma’am.’

‘And we still don’t know why?’

‘No ma’am. There are no obvious financial incentives because of the way the shareholding of Empire of Spice is structured. Mrs Roy’s children already enjoy the trappings of considerable wealth.’

‘What about Parr-Fielding? He’s in debt, has previous convictions and I understand that he was caught snooping round the crime scene?’

Gillard smiled. Prisha’s partner seemed to be the chief constable’s favourite suspect. ‘His DNA didn’t show up anywhere, so he’s in the clear for now. I’ll continue to monitor him.’

‘All right, Craig. Good work on this. I’m not going to release Waddington until we have a bit more at least. I’ll be away most of this week, but you’ll still be able to get hold of me.’