"It's some sort of secret work for Uncle Sam, I guess," hazarded Jack, "but what it is I've no idea. Anyhow it's none of our business."
The boys little guessed, when Jack made that remark, how very much their business Captain Simms' secret mission was to become in the near future.
CHAPTER V.
NIGHT SIGNALS.
After supper Captain Simms suddenly announced that he wished to make a trip to the mainland to the town of Clayton. He wished to send an important telegram to Washington, he explained.
"How are you going?" asked Jack. "The hotel boat has stopped running for the day."
"I know that, but I'll go on the Skipjack. You lads want to come?"
"Do we? I should say we do."
"You lads must be full of springs from the way you're always jumping about," remarked Uncle Toby, with a smile, "but I suppose it's boy nature."