Halifax was safely reached, nothing more exciting having occurred between that port and New York than a severe thunder storm, and, after the usual inspection by the English authorities, the ship bearing the moving picture boys was once more on her way.

The lifeboat drills were rigorously kept up, and now, as the real voyage had begun, with each day bringing nearer the dreaded submarine peril, orders were given in regard to the display of lights after dark. The passengers were ordered to be in readiness, to keep life preservers at hand, and were told that as soon as the actual danger zone was reached it would be advisable for all to keep their clothing on at night as well as during the day.

"But the destroyers will convoy us, won't they?" asked Charlie Anderson.

"Oh, yes! They'll be on hand to greet us when the time comes," answered Blake. "Uncle Sam's as well as King George's. But, for all that, a submarine may slip in between them and send a torpedo to welcome us."

"Then's when I'm going to get busy with the small camera," declared Joe.

"A heap of good it'll do you to get some pictures of it, if the ship is blown up," remarked his chum.

"Oh, well, I'm going to take a chance. Every ship that's torpedoed doesn't sink, and we may be one of the lucky ones. And if I should happen to get some views of a destroyer sinking a submarine—why, I'd have something that any camera man in the world would be proud of!"

"That's right!" agreed Blake. "But don't take any chances."

Joe promised to heed this advice, and he was really enthusiastic about his chance of getting a view of an oncoming torpedo. That he might get views of a warship or a destroyer sinking one of the Hun undersea boats was what he dreamed about night and day.

It was the day before they were actually to enter the danger zone—the zone marked off in her arrogance by Germany—that something occurred which made even cautious Blake think that perhaps they were justified in their suspicions of the Frenchman.

The usual lifeboat drills had been held, and the passengers were standing about in small groups, talking of what was best to be done in case the torpedo or submarine alarm should be given, when Macaroni, who had been down in the cabin, came up and crossed the deck to where Blake and Joe were talking to two young ladies, to whom they had been introduced by the captain.

By one of the many signs in use among moving picture camera men, which take the place of words when they are busy at the films, Macaroni gave the two chums to understand he wanted to speak to them privately and at once. The two partners remained a little longer in conversation, and then, making their excuses, followed their helper to a secluded spot.

"What's up?" demanded Joe. "Have you made some views of a torpedo?"

"Or seen a periscope?" asked Blake.

"Neither one," Charlie answered. "But if you want to see something that will open your eyes come below."

His manner was so earnest and strange, and he seemed so moved by what he had evidently seen, that Blake and Joe, asking no further questions, followed him.

"What is it?" Joe demanded, as they were about to enter their cabin, one occupied by the three of them.

"Look there!" whispered the helper, as he pointed to a mirror on their wall.

Blake and Joe saw something which made them open their eyes. It was the reflection of a strange conference taking place in the stateroom across the passageway from them, a conference of which a view was possible because of open transoms in both staterooms and mirrors so arranged that what took place in the one across the corridor was visible to the boys, yet they remained hidden themselves.

Blake and Joe saw two men with heads close together over a small table in the center of the opposite stateroom. The tilted mirror transferred the view into their own looking-glass. The men appeared to be examining a map, or, at any rate, some paper, and their manner was secretive, alone though they were.

But it was not so much the manner of the men as it was the identity of one that aroused the curiosity and fear of the moving picture boys—curiosity as to what might be the subject of the queer conference, and fear as to the result of it.

For one of the men was Lieutenant Secor, the Frenchman, and the other was a passenger who, though claiming to be a wealthy Hebrew with American citizenship, was, so the boys believed, thoroughly German. He was down on the passenger list as Levi Labenstein, and he did bear some resemblance to a Jew, but his talk had the unmistakable German accent.

Not that there are not German Jews, but their tongue has not the knack of the pure, guttural German of Prussia. And this man's voice had none of the nasal, throaty tones of Yiddish.

"Whew!" whistled Joe, as he and Blake looked into the tell-tale mirror. "That looks bad!"

"Hush!" cautioned Blake. "The transoms are open and he may hear you."

But a look into the reflecting glasses showed that the two men—the Frenchman and the German—had not looked up from their eager poring over the map, or whatever paper was between them.

"How long have they been this way?" asked Blake, in a whisper, of Charlie.

"I don't know," Macaroni answered. "I happened to see them when I came down to get something, and after I'd watched them a while I went to tell you."

"I'm glad you did," went on Blake; "though I don't know what it means—if it means anything."

"It means something, all right," declared Joe, and he, like the others, was careful to keep his voice low-pitched. "It means treason, if I'm any judge!"

"Treason?" repeated Blake.

"Yes; wouldn't you call it that if you saw one of our army officers having a secret talk with a German enemy?"

"I suppose so," assented Blake. "And yet Lieutenant Secor isn't one of our officers."

"No, but he's been in our camps, and he's been a guest of Uncle Sam. He's been in a position to spy out some of the army secrets, and now we see him talking to this German."

"But this man may not be a subject of the Kaiser," said Blake.

"Sure he is!" declared Charlie. "He's no more a real Jew than I am! He's a Teuton! Germany has no love for the Jews, and they don't have any use for the Huns. Take my word for it, fellows, there's something wrong going on here."

"It may be," admitted Blake; "but does it concern us?"

"Of course it does!" declared Joe. "This Frenchman may be betraying some of Uncle Sam's secrets to the enemy—not only our enemy, but the enemy of his own country."

"Yes, I suppose there are traitorous Frenchmen," said Blake slowly, "but they are mighty few."

"But this means something!" declared Macaroni.

And Blake, slow as he was sometimes in forming an opinion, could not but agree with him.

In silence the boys watched the two men at their queer conference. The tilted mirrors—one in each stateroom—gave a perfect view of what went on between the Frenchman and the German, as the boys preferred to think Labenstein, but the watchers themselves were not observed. This they could make sure of, for several times one or the other of the men across the corridor looked up, and full into the mirror on their own wall, but they gave no indication of observing anything out of the ordinary.

The mirrors were fastened in a tilted position to prevent them from swinging as the ship rolled, and as they did not sway there was an unchanged view to be had.

"I wonder what they're saying," observed Blake.

They could only guess, however, for though the men talked rapidly and eagerly, as evidenced by their gestures, what they said was not audible. Though both transoms were open, no sound came from the room opposite where the boys were gathered. The men spoke too low for that.

"I guess they know it's dangerous to be found out," said Joe.

"But we ought to find out what it's about!" declared Macaroni.

"Yes, I think we ought," assented Blake. "This Frenchman has been in our country, going about from camp to camp according to his own story, and he must have picked up a lot of information."

"And he knows about our pictures, too!"

"Well, I don't imagine what we have taken, so far, will be of any great value to Germany, assuming that Lieutenant Secor is a spy and has told about them," Blake said.

"We've got to find out something about this, though, haven't we?" asked Joe.

"I think we ought to try," agreed his chum. "Perhaps we should tell Captain Merceau. He's a Frenchman, and will know how to deal with Secor."

"Good idea!" exclaimed Joe. "If we could only get him down here to see what we've seen, it would clinch matters. I wonder——"

But Joe ceased talking at a motion from Blake, who silently pointed at the mirror. In that way they saw the reflection of the men in the other cabin. They arose from their seats at the table, and the map or whatever papers they had been looking at, were put away quietly in the Frenchman's pocket.

He and the German, as the boys decided to call Labenstein, spoke in whispers once more, and then shook hands, as if to seal some pact.

Then, as the boys watched, Lieutenant Secor opened the door of the stateroom, which had been locked. He stepped out into the corridor, and was now lost to view.

The next moment, to the surprise of Blake and his two friends, there came a knock on their own door, and a voice asked:

"Are you within, young gentlemen of the cameras? I am Lieutenant Secor!"