‘That is what one hopes. But one must admit that events have taken place there that might well shake the nerves of fond mammas—and papas also. The Games Mistress, the French Mistress, and yet another mistress—all murdered.’

‘As you say.’

‘I hear,’ said Mr Robinson, ‘(one hears so many things), that the unfortunate young woman responsible has suffered from a phobia about schoolmistresses since her youth. An unhappy childhood at school. Psychiatrists will make a good deal of this. They will try at least for a verdict of diminished responsibility, as they call it nowadays.’

‘That line would seem to be the best choice,’ said Poirot. ‘You will pardon me for saying that I hope it will not succeed.’

‘I agree with you entirely. A most cold-blooded killer. But they will make much of her excellent character, her work as secretary to various well-known people, her war record—quite distinguished, I believe—counter espionage—’

He let the last words out with a certain significance—a hint of a question in his voice.

‘She was very good, I believe,’ he said more briskly. ‘So young—but quite brilliant, of great use—to both sides. That was her métier—she should have stuck to it. But I can understand the temptation—to play a lone hand, and gain a big prize.’ He added softly, ‘A very big prize.’

Poirot nodded.

Mr Robinson leaned forward.

‘Where are they, M. Poirot?’

‘I think you know where they are.’

‘Well, frankly, yes. Banks are such useful institutions are they not?’

Poirot smiled.

‘We needn’t beat about the bush really, need we, my dear fellow? What are you going to do about them?’

‘I have been waiting.’

‘Waiting for what?’

‘Shall we say—for suggestions?’

‘Yes—I see.’

‘You understand they do not belong to me. I would like to hand them over to the person they do belong to. But that, if I appraise the position correctly, is not so simple.’

‘Governments are in such a difficult position,’ said Mr Robinson. ‘Vulnerable, so to speak. What with oil, and steel, and uranium, and cobalt and all the rest of it, foreign relations are a matter of the utmost delicacy. The great thing is to be able to say that Her Majesty’s Government, etc., etc., has absolutely no information on the subject.’

‘But I cannot keep this important deposit at my bank indefinitely.’

‘Exactly. That is why I have come to propose that you should hand it over to me.’

‘Ah,’ said Poirot. ‘Why?’

‘I can give you some excellent reasons. These jewels—mercifully we are not official, we can call things by their right names—were unquestionably the personal property of the late Prince Ali Yusuf.’

‘I understand that is so.’

‘His Highness handed them over to Squadron Leader Robert Rawlinson with certain instructions. They were to be got out of Ramat, and they were to be delivered to me.’

‘Have you proof of that?’

‘Certainly.’

Mr Robinson drew a long envelope from his pocket. Out of it he took several papers. He laid them before Poirot on the desk.