‘So that’s the motive for murder?’

‘I think so, yes. Once Mrs Roy was dead, Zayan expected he could gradually drop the pretence.’

‘But Zayan claimed to adore her.’

‘He had to, but I’m sure he actually detested her. He was thinking ahead, whereas Harry was happy to muddle along, with his great big circle of supportive friends, particularly Morag. Harry would spend his time playing a bit of cricket with the disabled kids, falling asleep over the accounts, pulling in the money, and have Zayan to himself when he got home. It was probably all he wanted. But Zayan is a dreamer, and ambitious. He wanted more. Remember, he lives just one floor beneath Harry, and they could spend plenty of time together without anyone knowing. That would just never be possible again if a marriage really did go ahead.’

‘Where’s the evidence?’

‘I’m still working on that.’

She laughed. ‘You’re going to need plenty to back up this theory. And before you see Rigby tomorrow morning. So do you think Harry was in on it?’

‘God, no. He really did adore his mother.’

‘But hang on, Craig, I’m confused. Didn’t you just tell me that the wedding is now going ahead?’

‘Yes, because of the one aspect that Zayan never really thought about. Money. The collapse of Nosh2U leaves EoS dangling by a thread. If the rest of the family has vetoed a takeover by the hated Johnny Lam, which is what the bid rejection seems to imply, it leaves the marriage dowry as the only way out.’

‘Wow. Zayan must be pissed off.’

‘That, I’m guessing, is why he stormed out of the funeral. He probably wanted to know why Sonali was there, and put two and two together.’

‘But what about Morag?’

‘I’m not sure, but I think she is the cover story. I was looking at them, and they just seemed so much more like brother and sister.’

‘All right, so Harry is either gay or bisexual, and most of his family never guessed. That’s plausible. But the murderer can’t be Zayan Lal. He voluntarily came in to Epsom police station today to give a DNA swab and photocopies of his flight bookings, which show him arriving in the UK on the Wednesday, three days after Mrs Roy was killed. Carl separately dug up the Heathrow e-gate arrival record, which confirms it. You’ve seen that too, haven’t you?’

Gillard sighed. ‘I did glance at it, yes.’

‘Harry Roy and Zayan Lal sat in adjacent seats in business class on the Air India flight going out from Heathrow to Mumbai more than two weeks before she was killed. Harry sent in that proof more than a week ago, and we confirmed his arrival details. And now we have Lal’s Heathrow arrival proof too.’

Gillard said nothing.

‘It’s not just an alibi, Craig, it’s cast iron. We know when he went out, we know when he came back. When Mrs Roy was killed, he just wasn’t here.’