He paused and again he looked expectantly at Sir Roger, who seemed engrossed in fingering the lower button of his waistcoat.

"Neither Sage nor I have any desire to embarrass you or the Home Secretary," continued Colonel Walton, "but——"

"I'm sure of it, Walton, I'm sure of it, and so is Sir Roger." Again Mr. Llewellyn John looked across at his colleague who, seeming to lose interest in his lower waistcoat button, suddenly looked up.

"The question is, how long is this to continue?" he asked.

For some moments Colonel Walton did not reply. He appeared to be weighing something in his mind.

"We're up against the cleverest organisation in the world," he said at length, "and Sage believes that a single man controls the lot."

"Nonsense!" broke in Sir Roger. "This spy craze is pure imagination."

"In any case it causes the War Cabinet a great amount of concern," said Mr. Llewellyn John drily.

"I think," proceeded Colonel Walton, "that before the expiration of the four months stipulated for by John Dene, Department Z. will have justified itself."

"How?" demanded Sir Roger.