"Who?" enquired Colonel Walton.

"The Hun," replied Sage, as he sucked away contentedly at his pipe.

"He's never content to go for a single issue, or he'd probably have got the Channel ports. He's not content with concentrating on John Dene and his boat, he's after the plans. That's where he'll fail. Smart chap, John Dene."

For some moments the two men smoked in silence, which was finally broken by Sage.

"They'll try to get hold of John Dene, unless he's very careful, and hold him to ransom, the price being the plans."

"Incidentally, Sage, where did you get all this from?" enquired Walton.

Sage gazed at his chief through his gold-rimmed spectacles. "About three hundred yards west of the Temple Station on the Underground."

Colonel Walton glanced across at his subordinate; but refrained from asking further questions. "Have you warned Dene?" he enquired instead.

"No use," replied Sage with conviction. "Might as well warn a fly."

Colonel Walton nodded understandingly. "Still," he remarked, "I think he ought to be told."

"Why not have a try yourself?" Sage looked up swiftly from the inevitable contemplation of his finger-nails.

For fully a minute Colonel Walton sat revolving the proposal in his mind. "I think I will," he said later.

"He'll treat you like a superannuated policeman," was the grim retort.

"The Skipper wants to see us at eleven," said Colonel Walton, looking at his watch and rising. The "Skipper" was the name by which Mr.

Llewellyn John was known at Department Z. Names were rarely referred to, and very few doc.u.ments were ever exchanged. Colonel Walton picked up his hat from a bookcase and, followed by Sage, who extracted a cap from his pocket, left the room and Department Z. and walked across to Downing Street.

As Colonel Walton and Malcolm Sage were shown into Mr. Llewellyn John's room, the Prime Minister gave instructions that he was not to be disturbed for a quarter of an hour.

"Was the John Dene Report what you wanted, sir?" enquired Colonel Walton, as he took the seat Mr. Llewellyn John indicated.

"Excellent," cried Mr. Llewellyn John; then with a smile he added, "I was able to tell Sir Lyster quite a lot of things this morning. The Admiralty report was not ready until late last night. It was not nearly so instructive."

The main facts of John Dene's career had not been difficult to obtain.

His father had emigrated to Canada in the early eighties; but, possessing only the qualifications of a clerk, he had achieved neither fame nor fortune. He had died when John Dene was eight years old, and his wife had followed him within eighteen months. After a varied career John Dene had drifted to the States, where as a youth he had entered a large engineering firm, and was instantly singled out as an inventor in embryo.

Several fortunate speculations had formed the foundation of a small fortune of twenty thousand dollars, with which he returned to Toronto.

From that point his career had been one continual progression of successes. Everything he touched seemed to turn to gold, until "John's luck" became a well-known phrase in financial circles.

Unlike most successful business-men, he devoted a large portion of his time to his hobby, electrical engineering, and when the war broke out he sought to turn this to practical and patriotic uses.

"And when may we expect Mr. Dene's new submarine over?" enquired Malcolm Sage casually.

"Mr. Dene's new submarine!" Mr. Llewellyn John's hands dropped to his sides as he gazed at Sage in blank amazement. "His new submarine," he repeated.

"Yes, sir."

"What on earth do you know about it?" demanded Mr. Llewellyn John, looking at Sage with a startled expression.

"John Dene has invented a submarine," proceeded the literal Sage, "with some novel features, including a searchlight that has overcome the opacity of water. The thing is lying on the St. Lawrence River just below Quebec. Yesterday he called to see Sir Lyster Grayne, who brought him here with Admiral Heyworth."

Mr. Llewellyn John gazed in bewilderment at Malcolm Sage, his eyes shifted to Colonel Walton and then back again to Sage.

"But," he began, "you're watching us, not the enemy. Did you know of this?" he turned to the chief of Department Z.

Colonel Walton shook his head. "I haven't seen Sage since you telephoned yesterday until a few minutes ago," he said.

"Where--how----?" Mr. Llewellyn John paused.

"It's our business to know things, sir," was Sage's quiet reply.

"And yet you didn't report this to----" began Mr. Llewellyn John.

"It saves time telling you both at once," responded Sage, looking at his chief with a smile.

"Suppose you tell us how you found out," suggested Mr. Llewellyn John a little irritably.

"Does that matter, sir?" Sage looked up calmly from an earnest examination of the nail of his left forefinger.

For some moments Mr. Llewellyn John gazed across at Malcolm Sage, frowning heavily.

"Sage has his own methods," remarked Colonel Walton tactfully.

"Methods," cried Mr. Llewellyn John, his brow clearing, "it's a good job he didn't live in the Middle Ages, or else he'd have been burned.

I'm not so sure that he ought not to be burned now." He turned on Sage that smile that never failed in its magical effect.

"There are one or two links missing," said Sage. "I want to know where and when the _Destroyer_ will arrive, and what steps you are taking in regard to John Dene."

"All arrangements will be left in Mr. Dene's hands. He is----" Mr.

Lewellyn John paused.

"A little self-willed," suggested Sage.

"Self-willed!" exclaimed Mr. Llewellyn John. "He is a dictator in embryo."

"He happens also to be a patriot," said Sage quietly.

"Wait until you meet him," said the Prime Minister grimly.

"I have met him," said Sage quietly. "I trod on his toe last night at 'Chu Chin Chow.' We had quite a pleasant little chat about it. I think that is all I need trouble you with, sir," he concluded.

"And we are to see the thing through?" interrogated Colonel Walton, as Mr. Llewellyn John rose. "There won't be any----"

"No one else knows anything about it except Sir Lyster, Sir Bridgman and Admiral Heyworth. By the way," Mr. Llewellyn John added, "our Canadian friend has an idea that our Secret Service is run by superannuated policemen in regulation boots."

"I know," said Sage, as he followed his chief towards the door.

"Good-bye," cried Mr. Llewellyn John. "I'm sure I shall have to send you to the Tower, Sage, before I've finished with you."