commander; but a look at his face, which showed plainly how deeply
chagrined he was at the failure to keep the two under surveillance, told
the young moving picture operator that there was no ground for his
thought.

"They got away!" repeated Joe, as though he could hardly believe it.

"Yes, I regret to say that is what my officer reports to me. It is too
bad; but I will at once send out word, and they may be traced and
apprehended. I'll at once send word to the authorities." This he did by
the same messenger who had brought the intelligence that the Frenchman
and the German had secretly left.

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.

"However, I very much doubt if this was the case," the captain frankly
admitted. "They are such scoundrels themselves that they would naturally
suspect others of suspecting them. So they must have become aware of our
plans, and then they made arrangements to elude the guard I set over
them."

"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