He retailed the conversation that had taken place at the dinner-table. Poirot listened attentively.

‘Ah,’ he said. ‘I comprehend now. Nevertheless, it seems that the lady has turned the tables on you both rather neatly!’

Sir George swore freely.

Poirot watched him with some slight amusement, then he said:

‘You do not doubt that this theft is her doing—I mean, that she is responsible for it, whether or no she played an active part?’

Sir George stared.

‘Of course not! There isn’t any doubt of that. Why, who else would have any interest in stealing those plans?’

‘Ah!’ said Hercule Poirot. He leaned back and looked at the ceiling. ‘And yet, Sir George, we agreed, not a quarter of an hour ago, that these papers represented very definitely money. Not perhaps, in quite so obvious a form as banknotes, or gold, or jewellery, but nevertheless they were potential money. If there were anyone here who was hard up—’

The other interrupted him with a snort.

‘Who isn’t these days? I suppose I can say it without incriminating myself.’

He smiled and Poirot smiled politely back at him and murmured:

‘Mais oui, you can say what you like, for you, Sir George, have the one unimpeachable alibi in this affair.’

‘But I’m damned hard up myself!’

Poirot shook his head sadly.

‘Yes, indeed, a man in your position has heavy living expenses. Then you have a young son at a most expensive age—’

Sir George groaned.

‘Education’s bad enough, then debts on top of it. Mind you, this lad’s not a bad lad.’

Poirot listened sympathetically. He heard a lot of the Air Marshal’s accumulated grievances. The lack of grit and stamina in the younger generation, the fantastic way in which mothers spoilt their children and always took their side, the curse of gambling once it got hold of a woman, the folly of playing for higher stakes than you could afford. It was couched in general terms, Sir George did not allude directly to either his wife or his son, but his natural transparency made his generalizations very easy to see through.

He broke off suddenly.

‘Sorry, mustn’t take up your time with something that’s right off the subject, especially at this hour of the night—or rather, morning.’

He stifled a yawn.

‘I suggest, Sir George, that you should go to bed. You have been most kind and helpful.’

‘Right, think I will turn in. You really think there is a chance of getting the plans back?’

Poirot shrugged his shoulders.

‘I mean to try. I do not see why not.’

‘Well, I’ll be off. Goodnight.’

He left the room.

Poirot remained in his chair staring thoughtfully at the ceiling, then he took out a little notebook and turning to a clean page, he wrote:

Mrs Vanderlyn?

Lady Julia Carrington?

Mrs Macatta?

Reggie Carrington?

Mr Carlile?

Underneath he wrote:

Mrs Vanderlyn and Mr Reggie Carrington?

Mrs Vanderlyn and Lady Julia?

Mrs Vanderlyn and Mr Carlile?

He shook his head in a dissatisifed manner, murmuring: ‘C’est plus simple que c¸a.’