"Stop that!" commanded Trotter, sharply, leaping to grab the spy.

"I only want to say one word to this young scamp!" hissed Lemaire.

"I will not hurt him."

"You can wager he won't," added Captain Jack, clenching his fists and watching the other alertly. "Let him speak to me, if he wants."

Trotter thereupon halted, though he watched the Frenchman with lynx-like wakefulness.

Lemaire, however, merely leaned forward until he had placed his lips close to one of the young submarine captain's ears.

"See here," hissed the spy, "hold your tongue about everything, and make sure Gaston and myself are released. Else, no corner of the earth will be a safe place for you. You can find no place in the world where you will be safe from destruction--unless you get us out of this one bad fix!"

CHAPTER XXII

GALLANT, EVEN TO THE FOE!

"You may have him now," announced Captain Jack, ironically. "I reckon he has spoken his piece."

Trotter's answer was to leap upon the Frenchman, pinioning his arms behind him. Packwood snapped handcuffs over the prisoner's wrists.

"Here is the bullet that Hastings dug out of the tree--the one that was probably fired at me," added Captain Jack. "And here is M. Lemaire's cane-pistol. You can see whether the bullet fits the cane."

Trotter took them, with a swift, admiring look at Benson's cool, handsome face.

Then, guiding their prisoner, the Secret Service men moved off hastily, for two or three hundred beach walkers had just discovered that something exciting had happened, and were hurrying forward.

Lemaire was forced into the buggy and driven rapidly away. Once out of sight the Secret Service men turned, driving straight for the local jail.

Before anyone in the excited crowd could ask what had happened the submarine people had vanished.

These four hurried to a room that Mr. Farnum had reserved while they remained at Spruce Beach.

"What was it that rascally Frenchman whispered to you?" demanded the shipbuilder.

Jack promptly repeated the threat, whereat Mr. Farnum's face grew decidedly grave.

"The worst of it is, Jack, I think the fellow not only meant the threat, but has the connections necessary to carry it out," said the ship builder, slowly. "I am quite prepared to believe that these spies work in large groups, when necessary. I am beginning to think that it will be wise move to get you way from here--in time."

"That would give Gaston a fine chance to go clear," retorted young Benson. "I am a very important witness when his case comes up."

"You are also a very important young man for our submarine company,"

replied Jacob Farnum, "so important, in fact, that I don't want to have you put out of this world through any of their plots for revenge."

"But don't you see, sir, that, if I run away from here, the fellow Gaston is very likely to be liberated?"

"Let him go, then," urged Mr. Farnum, though it was plain that he spoke reluctantly.

"It's just what I won't do, sir. I wouldn't be a good citizen if I should allow a criminal to escape justice just because I was, afraid to stay and testify against him," argued Captain Jack.

"I admit the force of all you say," a.s.sented Mr. Farnum, slowly. "Yet, if I should find, after thinking it all over, that it will be best to instruct you to leave here quietly, you won't refuse to obey, will you?"

"Yes," declared Jack Benson.

"What? It would be the first time you ever balked at orders, then."

"But this is different, Mr. Farnum. I refuse to obey any order that will tend to defeat the ends of justice."

Jacob Farnum winced at that statement of the matter. He had been anxious only to save Jack from the attempts of a dangerous crowd.

"Jack is right," broke in David Pollard, decisively.

"When he puts the case in that way, I don't dare say that he isn't,"

admitted the shipbuilder. "At the same time, I can't bear the thought of the lad being butchered to gratify the grudge of any of the rascally crew that we've offended here at Spruce Beach."

A slight, rustling sound at the door caused them all to wheel about.

Jacob Farnum's eyes beheld a slip of white paper lying on the floor, just inside the door. Jack Benson saw it, also, but he sprang past the paper, pulling the door open.

Around a turn in the corridor the submarine boy heard the sound of fleet footsteps.

Jack pursued, but could find no one, and the sound of moving feet had also ceased. As soon as he was satisfied that he could not catch the prowler, the submarine boy returned to the room.

"Do you see this?" asked the shipbuilder, holding out the slip of paper.

"Another warning, I suppose?" Benson ventured.

"Yes; and it shows that you are being followed and watched. Something worse is almost certain yet to happen."

Jack took the slip of paper, reading these printed words:

"You have been fairly warned. Are you going to be a fool? Obey, or--"

That was all. The meaning of the words was plain enough, but Jack, with as cool a smile as ever, folded the slip, dropping it in one of his pockets.

"This will interest Trotter," he remarked.

"There is no use whatever in advising you, suppose?" asked the shipbuilder.

"If these threats were directed against you, would you cringe from them?" demanded the young submarine captain.

"Of course I wouldn't," replied Farnum, a sudden flash lighting his eyes as he spoke.

"Then why should you expect to see me turn coward?"

"I won't say another word about it, Jack!" replied the shipbuilder, gripping his captain's hand. "I have dreaded to see you go down under the mysterious a.s.saults of these scoundrels. I have hated to see a boy come to that harm while serving me. But I realize, now, that it would hurt you worse to run away than it would to stay and face any kind of punishment or even death itself."