"And you say that nobody but the officials directly connected with the craft has any knowledge of its whereabouts?" asked Rob with deep interest.
"As far as it is humanly possible to be certain, such is our positive belief."
"But where do we fit into all this?" sputtered Tubby, acutely coming to the main point.
"I am coming to that," was the response. "From what I have told you, you will have gathered that no ordinary class of watchmen could be trusted to keep quiet about what is to go forward on the island. Yet it is necessary to have sentries of some sort to keep constant watch that no one approaches unexpectedly. For that purpose we have adopted various mechanical precautions, such as submarine detector bells, etc. But our main reliance must be on human intelligence."
"I see," said Rob, nodding. The object of the officer's visit was beginning to dawn on him.
"To come straight to the point," went on the officer, "how would you boys like to take a camping trip to the South Carolina coast on Uncle Sam's service?"
"You mean to act as guards to the submarine?" almost shouted Rob.
"Just that," responded the officer. "I have——"
But a roar of cheers drowned any further remarks he might have had to make.
"I knew it would happen," cried Merritt when the riot had, in a measure, subsided.