‘Tchah! It is on the tip of my tongue.’

Major Riddle waited a minute or two, then as Poirot continued to frown perplexedly, he took up the interrogation once more.

‘When was the last time you saw Sir Gervase?’

‘At tea-time, in this room.’

‘What was his manner then? Normal?’

‘As normal as it ever was.’

‘Was there any sense of strain among the party?’

‘No, I think everybody seemed quite ordinary.’

‘Where did Sir Gervase go after tea?’

‘He took Mr Burrows with him into the study, as usual.’

‘That was the last time you saw him?’

‘Yes. I went to the small morning-room where I worked, and typed a chapter of the book from the notes I had gone over with Sir Gervase, until seven o’clock, when I went upstairs to rest and dress for dinner.’

‘You actually heard the shot, I understand?’

‘Yes, I was in this room. I heard what sounded like a shot and I went out into the hall. Mr Trent was there, and Miss Cardwell. Mr Trent asked Snell if there was champagne for dinner, and made rather a joke of it. It never entered our heads to take the matter seriously, I’m afraid. We felt sure it must have been a car back-firing.’

Poirot said:

‘Did you hear Mr Trent say, “There’s always murder”?’

‘I believe he did say something like that—joking, of course.’

‘What happened next?’

‘We all came in here.’

‘Can you remember the order in which the others came down to dinner?’

‘Miss Chevenix-Gore was the first, I think, and then Mr Forbes. Then Colonel Bury and Lady Chevenix-Gore together, and Mr Burrows immediately after them. I think that was the order, but I can’t be quite sure because they more or less came in all together.’

‘Gathered by the sound of the first gong?’

‘Yes. Everyone always hustled when they heard that gong. Sir Gervase was a terrible stickler for punctuality in the evening.’

‘What time did he himself usually come down?’

‘He was nearly always in the room before the first gong went.’

‘Did it surprise you that he was not down on this occasion?’

‘Very much.’

‘Ah, I have it!’ cried Poirot.

As the other two looked inquiringly at him he went on:

‘I have remembered what I wanted to ask. This evening, mademoiselle, as we all went along to the study on Snell’s reporting it to be locked, you stooped and picked something up.’

‘I did?’ Miss Lingard seemed very surprised.

‘Yes, just as we turned into the straight passage to the study. Something small and bright.’

‘How extraordinary—I don’t remember. Wait a minute—yes, I do. Only I wasn’t thinking. Let me see—it must be in here.’

Opening her black satin bag, she poured the contents on a table.

Poirot and Major Riddle surveyed the collection with interest. There were two handkerchiefs, a powder-compact, a small bunch of keys, a spectacle-case and one other object on which Poirot pounced eagerly.

‘A bullet, by jove!’ said Major Riddle.