'Of course you've heard about Professor Yule?' said Vogel urbanely.
'Of course. . . .' Simon's rendering of slight apologetic confusion was attained with an effort that no one could have felt but himself. 'Now I know who he is. ... But I hadn't placed him until that lady said something just now.' He looked at Yule with a smile of open admiration. 'It must have been an amazing experience, Professor.'
Yule shrugged, with a pleasant diffidence.
'Naturally it was interesting,' he replied frankly. 'And rather frightening. Not to say uncomfortable. . . . Perhaps you know that the temperature of the water falls rapidly when you reach really great depths. As a matter of fact, at five thousand feet it is only a few degrees above freezing point. Well, I had been so taken up with the other mechanical details of pressure and lighting and air supply that I actually forgot that one. I was damned cold!' He chuckled engagingly. 'I'm putting an electrical heating arrangement in my improved bathystol, and I shan't suffer that way next time.'
'You've decided to go down again, then?'
'Oh, yes. I've only just started. That first trip of mine was only a trial. With my new bathystol I hope to get down twice as far—and that's nothing. If some of the latest alloys turn out all right, we may be able to have a look at the Cape Verde Basin— over three thousand fathoms—or even the Tuscarora Trough, more than five miles down.'
'What do you hope to find?'
'A lot of dull facts about depth currents and globigerina ooze. Possibly some new forms of marine life. There may be some astounding monsters living and dying down there, and never seeing the light of day. We might even track down our old friend the sea serpent.'
'There are some marvellous possibilities,' said the Saint thoughtfully.
'And some expensive ones,' confessed Yule, with attractive candour. 'In fact, if it hadn't been for Mr Vogel they might not have been possibilities at all—my first descent just about ruined me. But with his help I hope to go a lot further.'
The Saint did not smile, although a sudden vision of Kurt Vogel as a connoisseur of globigerina ooze and new species of fish tempted him almost irresistibly. He saw beyond that to other infinitely richer possibilities—possibilities which had probably never occurred to the Professor.
He knew that Vogel was watching him, observing every microscopic detail of his reactions with coldly analytical precision. To show a poker-faced lack of interest would be almost as suspicious as breaking loose with a hungry stream of questions. He had to judge the warmth of his response to the exactest hundredth of a degree, if he was to preserve any hope of clinging to the bluff of complete unsuspecting innocence which he had adopted. In the next twenty minutes of ordinary conversation he worked harder than he had done for half his life.
'. . . so the next big descent will show whether there's any chance of supporting Wegener's theory of continental drift,' concluded the Professor.
'I see,' said the Saint intelligently.
A man wandering about the terrace with a large camera pushed his way to their table and presented a card with the inscription of the Agence Francaise Journalistique.
Yule grinned ruefully, like a schoolboy, and submitted blushingly to the ordeal. The photographer took two snapshots of the group, thanked them, and passed on with a vacuous air of waiting for further celebrities to impinge on his autocratic ken. A twice-divorced countess whom he ignored glared after him indignantly ; and Kurt Vogel beckoned a waiter for the addition.
'Won't you have another?' suggested the Saint.
'I'm afraid we have an engagement. Next time, perhaps.' Vogel discarded two ten-franc notes on the assiette and stood up with a flash of his bloodless smile. 'If you're interested, you might like to come out with us on a trial trip. It won't be very sensational, unfortunately. Just a test for the new apparatus in moderately deep water.'
'I should love to,' said the Saint slowly.
Vogel inclined his head pleasantly.
