“How did they do that?” asked Blake.

“By a trick.  One of them pretended to be ill and asked that the surgeon be summoned.  This was the German.  And when the guard hurried away on what he supposed was an errand of mercy, the two rascals slipped away.  They were soon lost in the crowd.  But we shall have them back, have no fear, young gentlemen.”

But, all the same, Blake and his chums had grave doubts as to the ability of the authorities to capture the two men.  Not that they had any fears for themselves, for, as Joe said, they had nothing to apprehend personally from the men.

“Unless they are after the new films we take,” suggested Charles.

“Why should they want them?” asked Blake.  “I mean, our films are not likely to give away any vital secrets,” he went on.

“Well, I don’t know,” answered the lanky helper, “but I have a sort of hunch that they’ll do all they can and everything they can to spoil our work for Uncle Sam on this side of the water, as they did before.”

“Secor spoiled the films before,” urged Blake.  “He didn’t know Labenstein then, as far as we know.”

“Well, he knows him now,” said Charles.  “I’m going to be on the watch.”

“I guess the authorities will be as anxious to catch those fellows as we are to have them,” resumed Blake.  “Putting a ship in danger of an attack from a submarine, as was undoubtedly done when Labenstein waved my flashlight, isn’t a matter to be lightly passed over.”

And the authorities took the same view.  Soon after Captain Merceau had sent his report of the occurrence to London to the officials of the English war office, the boys were summoned before one of the officers directing the Secret Service and were closely questioned.  They were asked to tell all they knew of the man calling himself Lieutenant Secor and the one who was on the passenger list as Levi Labenstein.  This they did, relating everything from Charlie’s accident with the Frenchman to the destruction of the submarine by the depth charge just after Labenstein had flashed his signal, assuming that this was what he had done.

“Very well, young gentlemen, I am exceedingly obliged to you,” said the English officer.  “The matter will be taken care of promptly and these men may be arrested.  In that case, we shall want your evidence, so perhaps you had better let me know a little more about yourselves.  I presume you have passports and the regulation papers?” and he smiled; but, as Blake said afterward, it was not exactly a trusting smile.

“He looked as if he’d like to catch us napping,” Blake said.

However, the papers of the moving picture boys were in proper shape.  But they were carefully examined, and during the process, when Joe, addressing Charles Anderson, spoke to him as “Macaroni,” the officer looked up quickly.

“I thought his name was Charles,” he remarked, as he referred to the papers.