‘You’re a lawyer. Good.’ The twinkling in the eyes spread to form a grin.

‘Not every policeman would agree,’ said Sara, trying to respond in kind.

‘My favourite profession.’ The grin settled into sympathy. ‘It must have been a nasty shock.’

‘Yes.’

‘Would you mind going over the timings?’

Sara felt a prickle of sweat beneath her armpits. She went through the evening; her return to the office, Morahan looking in, briefing him.

‘His mood?’ asked Buttler.

‘Same as always. Polite. Clear. Positive.’

‘And then?’

‘I went home and soon after received a text from Sir Francis – around 8.30, I think – asking if I could come back in an hour or so if I was able to. I was surprised but assumed he wanted to go through some papers.’

‘Do you have that text?’

‘Yes, of course.’

‘Could I see it, please?’

‘It was sent confidentially.’

‘I understand but it might help.’

‘I suppose it can do no harm now.’

Sara took her phone from a pocket and went to the inbox. She felt a sudden panic. She looked again, scrolled up and down. The text wasn’t there. Did she delete it? She hardly ever did – phones could store millions. A rash of sweat spread to her neck and chest – she hoped it wasn’t showing. Perhaps, with everything that was going on, she’d somehow deleted it on autopilot? Yet her memory was usually faultless.

Feeling the heat in her cheeks, she looked up at Buttler. ‘I’m sorry, the text appears to have been deleted. I don’t understand it as I don’t remember doing that. Perhaps I did – seeing the body put me in rather a spin.’

He eyed her for a few seconds. ‘You mean seeing the Chairman’s body half-naked and dead may have impelled you to delete his text?’

‘Yes. No. I mean there was nothing unusual about the text. Just saying he wanted to discuss something in the paperwork.’

‘I see.’ He paused. ‘Never mind,’ he continued brightly, ‘we should be able to retrieve it. And it’ll be on Sir Francis’s phone too.’

She looked down at her phone to check the ‘Sent’ box and breathed a sigh of relief. ‘Look, here’s my text replying to him, saying I’m coming in. That shows I must have got his.’

Buttler, expressionless, inspected her for a split-second. ‘Perhaps you could continue.’

‘I got the tube – it’s an easy journey for me which he knew so perhaps that’s why he felt able to make the suggestion. I arrived soon after 9.30. His door was shut, so I poked my head through it but there was no sign of him. I returned to my office and waited, assuming he was taking a break. I was bemused. I wondered if I’d misunderstood something and he’d wanted me to come to his home.’

‘You had his address?’

‘Yes, he’d given it to me.’