‘That person must have been horrified, on Saturday morning, to see – as I saw – you sitting with Clementine in the Murder Spiral, talking together.’ Rosalind motioned to the window, remembering how she’d felt, after Isobel’s talk of an affair, seeing Hugh with such a pretty, young girl, having what was clearly an emotional conversation. ‘And maybe they cornered Clementine later that day. Perhaps they just wanted to talk. Or maybe they went in there knowing they wanted to kill her. We can’t be sure. But we do know she ended up dead before the sun went down on Saturday, and one of you threw her body in the reeds and hoped it sank.’

‘And that could have been the end of it,’ Caro said. ‘If it wasn’t for something Marcus said as we all stood on the steps, watching Clementine drive away in that vintage car. He said that he knew she had family nearby. Because, being Marcus, he couldn’t know something and not hint at it, tease others with it – or use it. I suspect he came to you afterwards – or maybe you even approached him – and asked what it would take to keep him quiet about Clementine’s existence?’ She stared at Isobel and, after a moment, Isobel flinched.

‘He wanted money to keep the secret,’ she admitted. ‘I said I needed to talk to Hugh.’

Her husband gave her a strange look. ‘You didn’t, though. You never mentioned it to me.’

‘Because he was dead before I got the chance!’ Isobel’s frustration leaked out in her angry words. ‘He had a heart attack! He had heart problems! And I, for one, do not appreciate this amateur hour, mock interrogation. We are not supporting actors in your film, nor are we idiots. Nothing you say here has any weight, and none of you have any proof. I’ve half a mind to fetch the policeman from the front door and have you all thrown out!’

‘No need, Mrs Davenport.’ Detective Chief Inspector Larch lounged in the doorway to the study, unseen until he wanted to be. Rosalind didn’t bother trying to hide her smile this time. He was early. ‘And I’d quite like to hear the rest of what our Lady Detectives have to say.’

Isobel scowled but stayed silent.