At that moment he heard the voices of Raxel and Crantor coming down the corridor outside. Simon slid noislessly across the room and stood motionless at the side of the door, in such a position that if it were opened he would be hidden.
His intuition had served him well, for he had hardly taken up his position when the handle rattled under somebody's hand, and there was a knock.
The Saint kept silence. The knock was repeated, and then the door opened. Simon held his breath, but Raxel only took one step into the room.
"He's not here," said the Professor's voice. "We might have expected that he was out. If I have correctly diagnosed the relationship between our Mr. Smith and our Miss Tregarth, one might safely say that he would not have let her leave without trying to get at least a few minutes' conversation with her."
"Thasso," said Crantor. "He seems to spend most of his time out of doors, walking. I guess he's out on a tramp now."
"We shall be ready for him when he returns," said Raxel, and the door closed.
Simon breathed again. The ancient ruse of hiding behind an opening door had worked for the thousandth time in history. He waited a moment, and then opened the door a cautious two inches. He was in time to hear another door close farther up the passage, and crept out.
He padded down the corridor on tiptoe, listening at each door as he passed, and located the two men in the laboratory.
He paused, listening. Their voices came to him quite distinctly. Raxel was speaking.
"The Megantic makes a steady twenty-five knots. My inquiries have been very complete. Here is the route--I have marked it out in red ink for you. They sail punctually at six o'clock to-morrow morning. By six o'clock on Thursday morning they should therefore be--here."
"That's right," said Crantor. "Here, pass me those compasses. I'll just check that, and work out ithe position now."
There was a silence, and then Crantor spoke again.
"I've jotted down the position against your imark," he said, and mentioned some figures. "So that's that. We've only got to wait till Smith comes back, and then we can be off."
"I've told. Tope to watch for him and report as soon as he arrives." said Raxel.
"What are you doing about Duncarry?" asked Crantor.
"For a time," answered Raxel, "I thought of enlisting him. He seemed to me to have distinct possibilities. But I have since revised that opinion. It is just an idea of mine--I feel that Duncarry might be dangerous. We will leave him behind."
"Right," said Crantor. "My bag's packed. If yours is ready we might send them down to the boat now. Then we can beat it as soon as we've got rid of Smith."
Simon Templar turned the handle and kicked the door open. He stepped into the room. Crantor jumped up with an exclamation, but the Professor was unperturbed.
"We have been expecting you, Mr. Smith," he remarked,
"Then you've got whatyou wanted, old dear," said the Saint cheerfully. "Stick your hands up, both of you."
He showed his gun, and Crantor obeyed, but Raxel's hand went to his pocket, and Simon pressed the trigger.
Nothing happened.
"It is now your turn to put up your hands, Mr. Smith," said Raxel, and his silenced automatic gleamed in his hand. "It was careless of you to leave your gun in your bedroom when you went to your bath this morning, but it gave me an invaluable opportunity of unloading it."
Simon's hands went up slowly.
"I congratulate you," he said.
"You flatter me," said the Professor, "it was really quite easy. On the other hand, I am able to thank you for saving us the trouble of waiting for you any longer."
The Saint smiled.
"If the bit of conversation I heard before I came in hadn't been so helpful, you might have had to wait a lot longer," he murmured, "However-- since we're all happy, may I smoke?"
Raxel produced his own case.
"So," he remarked, "you are no longer mystified?"
"Well--no," admitted the Saint. "Not exactly. I never imagined you and Marring and Crantor went into partnership to discuss new ways of accelerating the growth of sweet peas. On the other hand, I definitely didn't know what was going on, though I've been watching you ever since you teamed up. Then when I took a peek at your workshop--"
"You were enlightened?"
"To the extent of four or five candlepower," said the Saint carefully. "I won't say that I jumped to the meaning of the bottled onions right away, and the diphenylcyanarsine was 'way beyond my scienitific powers, but I got some expert advice that cleared a lot of air. And now you've answered the Mother questions yourselves, so that lets me out. It was only Betty Tregarth that I hadn't one good clue about."
"Ah--you were interested?"
Simon lounged against the wall. He had no idea what turn the situation would take next; so, characteristically, he declined to overheat his brain with the problem.
"I was curious," he said. "But even that riddle is rapidly untangling itself with the help of other information recently acquired. I seem to remember that when you murdered Inspector Henley, who was also interested in you, there was a woman in the house. At least, the police found traces of her presence, though they had nothing to help them to identify her. And it appears that Betty Tregarth is your tame chemist." The Saint's eyes rested thoughtfully on Bernhard Raxel. "Now suppose-- just suppose--a trio of tough babies had figured out a dandy scheme of up-to-date piracy, using poison gas and all that sort of dope. They'd want someone to make the stuff for them, wouldn't they? Anyone out of the street can't walk into a shop and ask for half a dozen cylinders of assorted smells to be sent round right away in a plain van. And the number of crooked chemists isn't so colossal that people would be queuing up in front of your house to get the billet. But suppose you had located a very good woman for the job, full of qualifications and knowledge, but still feminine enough to be frightened-- and then suppose you framed her for a murder that you were going to commit anyway, framed her well enough to convince her even if the police never noticed it--and then demanded her services as the price of your protection? It might work--women have been blamed fools before now--and a scheme like that would just suit your kind of brain.
He read the accumulating confirmation in Raxel's eyes even while he was elaborating his theory, and laughed.
That's about it, isn't it Uncle?' He drawled.
Raxel nodded calmly.
"Your logic is admirable, Mr. Smith, If you had not been so foolish as to take up this case, your powers might have won you a high position in your profession. As it is---" He shrugged. "I fear our time is short. Will you kindly precede us to the cellar?" y "With all the pleasure in life," answered the Saint politely.
They went down the corridor and down the stairs in procession. On the ground floor, Crantor opened a door under the staircase, and went through, switching on a torch as he did so. The Saint saw a flight of stone stairs leading down into darkness.
"What's going to happen when I get down there?" he asked.