"I suppose you know more about it than I do, sir," he submitted humbly, "but I always feel the danger's exaggerated. There must be plenty of honest agents."

"There are, Old Man," rumbled Lemuel. "But we get saddled with the crimes of those who aren't."

Shortly afterwards, the conversation reverted to purely business topics; and the Saint, receiving a hint too broad to be ignored, excused himself.

Lemuel and the Saint left for England the next morning, and at the hour when he took off from Waalhaven Aërodrome on the last stage of the journey (they had descended upon Rotterdam for a meal) Simon was very little nearer to solving the problem of Francis Lemuel than he had been when he left England.

The inspiration came to him as they sighted the cliffs of Kent.

A few minutes later he literally ran into the means to his end.

It had been afternoon when they left the Tempelhof, for Mr. Lemuel was no early riser; and even then the weather had been breaking. As they travelled westwards it had grown steadily worse. More than once the Saint had had to take the machine very low to avoid clouds; and, although they had not actually encountered rain, the atmosphere had been anything but serene ever since they crossed the Dutch frontier. There had been one very bumpy half-hour during which Mr. Lemuel had been actively unhappy. . . .

Now, as they came over English ground, they met the first of the storm.

"I don't like the look of it, Templar," Mr. Lemuel opined huskily, through the telephones. "Isn't there an aërodrome near here that we could land at, Old Man?"

"I don't know of one," lied the Saint. "And it's getting dark quickly-I daren't risk losing my bearings. We'll have to push on to Croydon."

"Croydon!"

Simon heard the word repeated faintly, and grinned. For in a flash he had grasped a flimsy clue, and had seen his way clear; and the repetition had confirmed him in a fantastic hope.