‘I’m frightened. Rose.’

Rosemary frowned.

‘But there’s no earthly need to be frightened,’ she declared in a peeved tone. ‘I told you, Dot, I’ve solved the mystery. I know who the murderer is.’

Dorothy did not seem to hear. She gazed past Rosemary at the window, where the light was starting to fade.

They’ll send me to hospital,’ she said. ‘I know they will. And once they’ve got me there, they’ll keep me, with tubes and wires stuck in me, like an animal in a laboratory. I won’t even be able to die, Rose. What kind of life is that, when you aren’t able to die?’

‘Nonsense!’ cried Rosemary scornfully.

Dorothy clasped her hand.

‘And you won’t be there to say “Nonsense!”. That’s what I mind most of all, Rose. That you won’t be there.’

Rosemary looked away, disconcerted by the intensity of terror in her friend’s voice. Then, with a visible effort, she turned back.

‘Pull yourself together, Dot!’ she snapped. There’s simply no time for this sort of silliness. We’ve got work to do. There’s a killer on the loose, and he-or she-may strike again at any moment.’

Dorothy’s gaze gradually lost its intensity. She relaxed her grip on Rosemary’s hand and took up her knitting again.

’Remind me where we’d got to,’ she said.

Rosemary released a long sigh.

‘Like Roland Ayres, Hilary was found dead in her bed one morning,’ she went on. ‘Dr Morel seemed satisfied that she had died of natural causes, and in due course signed a death certificate to that effect, but we knew better.’

Dorothy nodded.

‘The rat poison kept in the potting shed…’

‘…accessible through the kitchen garden…’

‘…where all the guests went at one time or another in the days preceding Hilary’s death…’

‘…under a variety of more or less flimsy pretexts ranging from replacing a missing croquet hoop to questioning the gardener about his begonias.’