Hawthorne knew a lot about computers. He had mentioned he had someone who could help him in London and I had actually met him. He was a neighbour, a young man with muscular dystrophy, who sat in a room surrounded by industrial-sized computers and high-tech paraphernalia and helped Hawthorne hack into the police computer system whenever he needed information. Just for fun, he had even hacked into my phone.

‘How can you be so sure it’s a he?’ I asked.

‘There’s something about her texts that make me think they’re addressed to a man.’ Hawthorne was still holding the phone in his hand. ‘If it was a girlfriend, I think she’d be a bit more personal. Also, unlike her, he doesn’t use any abbreviations.’

‘Mrs le Mesurier knew who killed her husband,’ Torode said. ‘She was protecting him.’

‘She saw something out of her bedroom window last night,’ Hawthorne admitted. He was angry with himself. ‘I knew she was lying to me when I spoke to her this morning. She was too bloody insistent. Even if I had looked out of the window – and I didn’t – it would have been too dark . . . But in the next breath she was telling me that there were lights on in the Snuggery, which would have lit up anyone who approached. A double lie.’

‘Shame you didn’t tell me this sooner,’ Torode muttered.

‘Shame your people let her leave,’ Hawthorne replied.

He was still thumbing through the other messages on the phone. It’s interesting how we all carry around with us a complete record of our lives, where we’ve been, what we’ve been thinking at any given time. Writing the biography of people born in the twenty-first century will be incredibly easy because the researchers won’t have to do any work. It’ll all be there, spelled out in minute detail.

Helen le Mesurier had texted Nora Carlisle with shopping lists and cleaning instructions, but it was all quite brisk, with no sign of the fondness that the housekeeper had suggested. She had maintained a brisk, quite business-like relationship with her husband; none of the texts between them were more than half a dozen words. On the other hand, she had sent gushing messages to ‘JF’ in Paris and I was just glad that she hadn’t attached photographs. JF wasn’t alone. There was Martin, Bobby, Otto, Sergei . . . a long list of men with whom she had been entwined. Hawthorne had to scroll through a string of messages before he found the texts he was looking for. They were spread out over a week. They had been sent six months ago and whoever had received them had replied by phone, as if they didn’t want to commit themselves to anything in writing.

Hi, Colin. No regrets. You warm, funny, kind man. Talk soon. ILU.

Don’t blank me, C. What happened happened. Je ne regrette etc. Let’s talk soon.