"No, you can rest easy about that," said Fred. "There won't be anybody on board except the Go Ahead boys and you."
"Well, then," said Sam, "if that's the case then we'll have to keep a sharp watch on the Black Growler."
Sam's manner more than the words he spoke impressed the boys with the fact that he was holding back something that he had heard or knew concerning the possibilities of trouble for the swift little motor-boat. Just what they were, neither Fred nor George could conjecture. Their confidence in Sam was great and when they departed from the boat-house they made light of his fears.
"Sam is a regular old kill joy," laughed George.
"There has to be somebody," said Fred, "to take the joy out of life. It wouldn't be worth living if that wasn't so."
"Well, Sam does his best," said George with a laugh, "and the only reason why he doesn't succeed is because his bark is worse than his bite. We know he doesn't mean half he says."
"But why does he seem so worried about something happening to the Black Growler?"
"Oh, I don't know," said George. "That's just one of his notions, I guess."
It was not long, however, before both boys were excitedly aware that Sam's forebodings had been based upon a knowledge greater than that possessed by any of the Go Ahead boys.