When this had been done, and the boys had got themselves ready to go ashore and report, Captain Merceau told them how it had happened. He had given orders, following the report made by Blake and his chums, that Secor and Labenstein should be kept under careful watch. And this was to be done without allowing them to become aware of it.

"Which is my only excuse," said the captain, with a smile. "Now I am going to see if we can not apprehend that German and his French fellow-conspirator." But, as may be guessed, "Henry Littlefield" was not to be found, nor Lieutenant Secor, nor Levi Labenstein. "Labenstein probably wrote that letter accusing us and mailed it just to make trouble because we suspected him and Secor," said Blake.

"Labenstein, of course, would be with the German forces, and since Secor is a traitor he would be there also. Of course it may not have been those fellows, but some other two men who had learned through their spies that we were here taking pictures and wanted them for their own purposes." "The question is, can we get them back?" put in Charlie, scowling in the direction of the Germans.

Much good may it do him!" As Labenstein passed the stateroom where Lieutenant Secor was quartered, that door opened softly, but not until the German was beyond it. And then Blake saw the Frenchman peer out as though to make sure his fellow-conspirator was fairly on his way. After that the lieutenant himself emerged and softly followed the German. "Both of 'em at it," mused Blake.

"What two fellows were they you saw?" asked Joe. The soldier explained, giving as many details as he could remember, and Charlie cried: "Lieutenant Secor for one the chap in the blue. A French traitor!" "He did have a uniform something like the French," admitted the private. "The other was a Fritz, though." "Labenstein!" murmured Joe.

"And the price?" asked Labenstein, as his hand quickly went into his pocket. "Is nothing," answered Blake. "It is a gift." "Ah, but, my dear sir, that is too much! I could not think of taking it without pay!" insisted Mr. Labenstein, as he flashed on the light and then slipped the switch back in place again. "I protest that I must pay you."

So that young man resumed: "Well, I'll tell you what I saw: Labenstein was leaning over the rail on the side where the submarine showed, and he was holding a big white cloth over the side." "A big white cloth?" cried Joe. "That's what it was," went on Blake. "It looked to me like a signal." "Do you mean a signal of surrender?" asked Charlie. "A white flag?

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.

However, the depth charge solved that question. "I had to escape from the ship with him to lull his suspicions against me. Then I went into the German ranks with him, being thought a deserter! That was hard for me, but I had my duty to perform. "The rest you know. It was by a mere chance that Labenstein, when I was with him, came upon your films after the gas attack.

As Blake and Joe had remarked, they had neither heard nor seen anything of Secor or Labenstein since they came from England. The men might have been arrested, but this was hardly likely. "Even if they were we wouldn't hear of it," said Blake. "But I hope, if they are under arrest, they'll hold them until we can tell what we know of them." "Same here," agreed Joe.