‘I suppose you’ve got a book on fungi?’ said Wexford.

‘Here.’ This also was produced from the drawer. British Fungi, Edible and Poisonous. ‘And here we are – shaggy caps.’

Burden had opened it at the Edible section and at a line and wash drawing of the species he held in his hand. He passed it to the chief inspector.

‘Coprinus comatus,’ Wexford read aloud, ‘a common species, attaining when full-grown a height of nine inches. The fungus is frequently to be found, during late summer and autumn, growing in fields, hedgerows and often in gardens. It should be eaten before the cap opens and disgorges its inky fluid, but is at all times quite harmless.’ He put the book down but didn’t close it. ‘Go on, please, Mike,’ he said.

‘Hood called for Corinne and they arrived together. They got there just after eight. At about eight-fifteen they all sat down to table and began the meal with avocado vinaigrette. The next course was to be the stew, followed by nut cutlets with a salad and then an apple-cake. Very obviously, there was no wine or liquor of any sort on account of Kingman’s prejudice. They drank grape juice from the shop.

‘The kitchen opens directly out of the living-dining room. Kingman brought in the stew in a large tureen and served it himself at the table, beginning, of course, with Corinne. Each one of those shaggy caps had been sliced in half lengthwise and the pieces were floating in a thickish gravy to which carrots, onions and other vegetables had been added. Now, ever since he had been invited to this meal, Hood had been feeling uneasy about eating fungi, but Corinne had reassured him, and once he began to eat it and saw the others were eating it quite happily, he stopped worrying for the time being. In fact, he had a second helping.

‘Kingman took the plates out and the tureen and immediately rinsed them under the tap. Both Hood and Corinne Last have told me this, though Kingman says it was something he always did, being fastidious about things of that sort.’

‘Surely his ex-girl friend could confirm or deny that,’ Wexford put in, ‘since they lived together for so long.’

‘We must ask her. All traces of the stew were rinsed away. Kingman then brought in the nut concoction and the salad, but before he could begin to serve them Hannah jumped up, covered her mouth with her napkin, and rushed to the bathroom.

‘After a while Corinne went to her. Hood could hear a violent vomiting from the bathroom. He remained in the living room while Kingman and Corinne were both in the bathroom with Hannah. No one ate any more. Kingman eventually came back, said that Hannah must have picked up some “bug” and that he had put her to bed. Hood went into the bedroom where Hannah was lying on the bed with Corinne beside her. Hannah’s face was greenish and covered with sweat and she was evidently in great pain because while he was there she doubled up and groaned. She had to go to the bathroom again and that time Kingman had to carry her back.