The Snug was fortunately abandoned once more. They sat Felicity on the chaise longue, while Rosalind prepared the drinks again, and Caro took the seat opposite their suspect.

‘So, what do you want to talk to me about?’

Rosalind placed her glass on the side table and leant forward. Caro could only see her hard, Dahlia stare out of the corner of her eye but, she had to admit, she did it perfectly. ‘You stole Lettice Davenport’s jewelled magnifying glass, and a bottle of poison, and put them in Posy’s room to frame her for the theft. We know this. What we don’t know, and what you are here to explain to us, is why.’

It was a bit of a stretch from what Ashok had told her, but it was the explanation that made the most sense. What else could she have been doing in Posy’s room?

Felicity glanced between Rosalind’s stony expression and Caro, as if trying to figure out who was playing good cop and who was bad cop.

Neither, kiddo. We’re both Dahlia, and you’re in trouble.

There was a long silence, the only noise the summer rainstorm battering the windows outside.

Finally, Felicity spoke. ‘I don’t … what did Ashok tell you? I know you spoke to him earlier.’ She looked rattled, and Caro allowed herself a smile. They had her.

‘That you told him Posy had asked to borrow your kindle, and left her door open so you could put it in her room,’ Caro said. ‘Except we know that she didn’t. So, care to explain what you were doing in Posy’s room?’

‘I wasn’t … it started as a game. A way to get back at Marcus, really.’

Rosalind blinked, twice. ‘At Marcus? Why?’

Clearly she hadn’t known Marcus as well as Caro and Felicity had.

‘Why, I can understand,’ Caro said. ‘It’s how that’s tripping me up. How did stealing the magnifying glass get back at Marcus?’

Felicity’s smile turned a little bit wicked. Caro couldn’t help but approve. She was pretty sure Dahlia would have too, if she’d ever met Marcus.

‘He was so caught up in his own genius about the murder mystery game – like he hadn’t ripped half of it straight from Lettice’s interviews where she talked about devising one for the family here at Aldermere. He wouldn’t stop going on about it, how he was the one who kept the Dahlia fandom going.’

‘While you and Clementine were doing all the actual work,’ Rosalind observed.

‘Exactly!’ Felicity was clearly thrilled at the vindication. ‘I knew he wanted to crow about what a success it would be, and that he’d be holding court over us for the rest of the weekend, going on about it. And I wanted, well, I wanted there to be a bigger, better mystery for people to solve.’