‘The active principle of the foxglove—digitalis—acts on the heart. Indeed, it is a very valuable drug in some forms of heart trouble. A very curious case altogther. I would never have believed that eating a preparation of foxglove leaves could possibly result fatally. These ideas of eating poisonous leaves and berries are very much exaggerated. Very few people realize that the vital principle, or alkaloid, has to be extracted with much care and preparation.’

‘Mrs MacArthur sent some special bulbs round to Mrs Toomie the other day,’ said Miss Marple. ‘And Mrs Toomie’s cook mistook them for onions, and all the Toomies were very ill indeed.’

‘But they didn’t die of it,’ said Dr Lloyd.

‘No. They didn’t die of it,’ admitted Miss Marple.

‘A girl I knew died of ptomaine poisoning,’ said Jane Helier.

‘We must get on with investigating the crime,’ said Sir Henry.

‘Crime?’ said Jane, startled. ‘I thought it was an accident.’

‘If it were an accident,’ said Sir Henry gently, ‘I do not think Mrs Bantry would have told us this story. No, as I read it, this was an accident only in appearance—behind it is something more sinister. I remember a case—various guests in a house party were chatting after dinner. The walls were adorned with all kinds of old-fashioned weapons. Entirely as a joke one of the party seized an ancient horse pistol and pointed it at another man, pretending to fire it. The pistol was loaded and went off, killing the man. We had to ascertain in that case, first, who had secretly prepared and loaded that pistol, and secondly who had so led and directed the conversation that that final bit of horseplay resulted—for the man who had fired the pistol was entirely innocent!

‘It seems to me we have much the same problem here. Those digitalin leaves were deliberately mixed with the sage, knowing what the result would be. Since we exonerate the cook—we do exonerate the cook, don’t we?—the question arises: Who picked the leaves and delivered them to the kitchen?’

‘That’s easily answered,’ said Mrs Bantry. ‘At least the last part of it is. It was Sylvia herself who took the leaves to the kitchen. It was part of her daily job to gather things like salad or herbs, bunches of young carrots—all the sort of things that gardeners never pick right. They hate giving you anything young and tender—they wait for them to be fine specimens. Sylvia and Mrs Carpenter used to see to a lot of these things themselves. And there was foxglove actually growing all amongst the sage in one corner, so the mistake was quite natural.’

‘But did Sylvia actually pick them herself?’

‘That, nobody ever knew. It was assumed so.’

‘Assumptions,’ said Sir Henry, ‘are dangerous things.’

‘But I do know that Mrs Carpenter didn’t pick them,’ said Mrs Bantry. ‘Because, as it happened, she was walking with me on the terrace that morning. We went out there after breakfast. It was unusually nice and warm for early spring. Sylvia went alone down into the garden, but later I saw her walking arm-in-arm with Maud Wye.’