For a moment even Blake, cool as he usually was, seemed to lose his head. He started in the direction of the Frenchman, against whom their suspicions were directed, thinking to speak to him, when Joe sprang from his chair.

"I'll show him!" exclaimed Blake's chum and partner, and this served to make Blake himself aware of the danger of acting too hastily. Quickly Blake put out his hand and held Joe back.

"What's the matter?" came the sharp demand. "I want to go and ask that fellow what he means by following us!"

"I wouldn't," advised Blake, and now he had control of his own feelings.

"Why not?"

"Because," answered Blake slowly, as he smiled at his chum, "he might, with perfect truth and considerable reason, say it was none of your business."

"None of my business? None of our business that he follows us aboard this ship when we're going over to get official war films? Well, Blake Stewart, I did think you had some spunk, but——"

"Easy now," cautioned Macaroni. "He's looking over here to see what the row's about. There! He's looking right at us."

The Frenchman did, indeed, seem to observe for the first time the presence of the boys so close to him. He looked over, bowed and smiled, but did not leave his place near the rail. He appeared to be occupied in looking at the docks and the shipping of New York harbor, glancing now at the tall buildings of New York, and again over at the Jersey shore and the Statue of Liberty.

"Come on back here—behind the deckhouse," advised Blake to his chum and Macaroni. "We can talk then and he can't see us."

And when they were thus out of sight, and the vessel was gathering way under her own power, Joe burst out with:

"Say, what does all this mean? Why didn't you let me go over and ask him what he meant by following us on board this vessel?"

"I told you," answered Blake, "that he'd probably tell you it was none of your business."

"Why isn't it?"

"Because this is a public vessel—that is, public in as much as all properly accredited persons who desire may go to England on her. Lieutenant Secor must have his passport, or he wouldn't be here. And, as this is a public place, he has as much right here as we have.

"And of course if you had asked him, Joe, especially with the show of indignation you're wearing now, he would have told you, and with perfect right, that he had as much business here as you have. He didn't follow us here; I think he was on board ahead of us. But if he did follow us, he did no more than some of these other passengers did, who came up the gangplank after us. This is a public boat."

Joe looked at his chum a moment, and then a smile replaced the frown on his face.

"Well, I guess you're right," he announced. "I forgot that anybody might come aboard as well as ourselves. But it does look queer—his coming here so soon after he spoiled our films; whether intentionally or not doesn't matter."

"Well, I agree with you there—that it does look funny," said Blake Stewart. "But we mustn't let that fact get the better of our judgment. If there's anything wrong here, we've got to find it out, and we can't do it by going off half cocked."

"Well, there's something wrong, all right," said Charlie Anderson, smiling at his apparently contradictory statement. "And we'll find out what it is, too! But I guess you're right, Blake. We've got to go slow. I'm going below to see if our stuff is safe."

"Oh, I don't imagine anything can have happened to it—so soon," said Blake. "At the same time, we will be careful. Now we must remember that we may be altogether wrong in thinking this Frenchman is working against us in the interests of our rivals, Sim and Schloss. In fact, I don't believe that firm cares much about the contract we have, though they have tried to cut in under us on other matters. So we must meet Lieutenant Secor halfway if he makes any advances. It isn't fair to misjudge him."

"I suppose so," agreed Joe. "Yet we must be on our guard against him. I'm not going to give him any information about what we are going across to do."

"That's right," assented Blake. "Don't talk too much to anybody—especially strangers. We'll be decent to this chap, but he is no longer a guest of our nation, and we don't have to go out of our way to be polite. Just be decent, that's all—and on the watch."

"I'm with you," said Joe, as Macaroni came back to say that all was well in their cabin where they had left most of their personal possessions. The cameras and the reels of unexposed film were in the hold with their heavy baggage, but they had kept with them a small camera and some film for use in emergencies.

"For we might sight a submarine," Joe had said. "And if I get a chance, I'm going to film a torpedo."

By this time the vessel was down in the Narrows, with the frowning forts on either side, and as they passed these harbor defenses Lieutenant Secor crossed the deck and nodded to the boys.

"I did not know we were to be traveling companions," he said, with a smile.

"Nor did we," added Blake. "You are going back to France, then?"

The lieutenant shrugged his shoulders in characteristic fashion.

"Who knows?" he asked. "I am in the service of my beloved country. I go where I am sent. I am under orders, Messieurs, and until I report in Paris I know not what duty I am to perform. But I am charmed to see you again, and rest assured I shall not repeat my lamentable blunder."

"No, I'll take good care you don't run into me," muttered Macaroni.

"And you, my friends of the movies—you camera men, as you call yourselves—you are going to France also?"

"We don't know where we are going, any more than you do," said Blake.

"Ah, then you are in the duty, too? You are under orders?"

"In a way, yes," said Blake. "We are, if you will excuse me for saying so, on a sort of mission——"

"Ah, I understand, monsieur! A thousand pardons. It is a secret mission, is it not? Tut! Tut! I must not ask! You, too, are soldiers in a way. I must not talk about it. Forget that I have asked you. I am as silent as the graveyard. What is that delightful slang you have—remember it no more? Ah, I have blundered! Forget it! Now I have it! I shall forget it!" and, with a gay laugh, he smiled at the boys, and then, nodding, strolled about the deck.

"He's jolly enough, anyhow," remarked Joe.

"Yes, and perhaps we have wronged him," said Blake. "The best way is not to talk too much to him. We might let something slip out without knowing it. Let him jabber as much as he likes. We'll just saw wood."

"I suppose he'd call that some more of our delightful slang, and translate it 'render into small pieces portions of the forest trees for the morning fire,'" laughed Joe. "Well, Blake, I guess you're right. We've got to keep things under our hats!"

"And watch our cameras and films," added Charlie. "No more accidental-purpose collisions for mine!"

In the novelty and excitement of getting fairly under way the moving picture boys forgot, for the time being, the presence of one who might be not only an enemy of theirs but of their country also. It was not the first time Blake and Joe had undertaken a long voyage, but this was under auspices different from any other.

The United States was at war with a powerful and unscrupulous nation. There were daily attacks on merchantmen, as well as on war vessels, by the deadly submarine, and there was no telling, once they reached the danger zone, what their own fate might be.

So even the start of the voyage was different from one that might have been taken under more favorable skies. Soon after they had passed into the lower bay word was passed that the passengers would be assigned to "watches," or squads, for lifeboat drill, in anticipation of reaching the dangerous submarine zone.

And then followed anxious days, not that there was any particular danger as yet from hostile craft, but every one anticipated there would be, and there was a grim earnestness about the lifeboat drills.

"I have been through it all before—when I came over," said Lieutenant Secor to the boys; "but it has not lost its terrible charm. It is a part of this great war!"

And as the ship plowed her way on toward her destination the anxious days became more anxious, and there were strained looks on the faces of all.