‘Such were the facts we had to go upon. If Jones had feloniously administered arsenic to his wife, it seemed clear that it could not have been done in any of the things eaten at supper, as all three persons had partaken of the meal. Also—another point—Jones himself had returned from Birmingham just as supper was being brought in to table, so that he would have had no opportunity of doctoring any of the food beforehand.’

‘What about the companion?’ asked Joyce—‘the stout woman with the good-humoured face.’

Sir Henry nodded.

‘We did not neglect Miss Clark, I can assure you. But it seemed doubtful what motive she could have had for the crime. Mrs Jones left her no legacy of any kind and the net result of her employer’s death was that she had to seek for another situation.’

‘That seems to leave her out of it,’ said Joyce thoughtfully.

‘Now one of my inspectors soon discovered a significant fact,’ went on Sir Henry. ‘After supper on that evening Mr Jones had gone down to the kitchen and had demanded a bowl of cornflour for his wife who had complained of not feeling well. He had waited in the kitchen until Gladys Linch prepared it, and then carried it up to his wife’s room himself. That, I admit, seemed to clinch the case.’

The lawyer nodded.

‘Motive,’ he said, ticking the points off on his fingers. ‘Opportunity. As a traveller for a firm of druggists, easy access to the poison.’

‘And a man of weak moral fibre,’ said the clergyman.

Raymond West was staring at Sir Henry.

‘There is a catch in this somewhere,’ he said. ‘Why did you not arrest him?’

Sir Henry smiled rather wryly.

‘That is the unfortunate part of the case. So far all had gone swimmingly, but now we come to the snags. Jones was not arrested because on interrogating Miss Clark she told us that the whole of the bowl of cornflour was drunk not by Mrs Jones but by her.

‘Yes, it seems that she went to Mrs Jones’s room as was her custom. Mrs Jones was sitting up in bed and the bowl of cornflour was beside her.

‘ “I am not feeling a bit well, Milly,” she said. “Serves me right, I suppose, for touching lobster at night. I asked Albert to get me a bowl of cornflour, but now that I have got it I don’t seem to fancy it.”

‘ “A pity,” commented Miss Clark—“it is nicely made too, no lumps. Gladys is really quite a nice cook. Very few girls nowadays seem to be able to make a bowl of cornflour nicely. I declare I quite fancy it myself, I am that hungry.”

‘ “I should think you were with your foolish ways,” said Mrs Jones.

‘I must explain,’ broke off Sir Henry, ‘that Miss Clark, alarmed at her increasing stoutness, was doing a course of what is popularly known as “banting”.

‘ “It is not good for you, Milly, it really isn’t,” urged Mrs Jones. “If the Lord made you stout he meant you to be stout. You drink up that bowl of cornflour. It will do you all the good in the world.”