Full of wonder, Matt and Dick raced down the slope.
"What is it, Carl?" demanded Matt.
"Feetprints," cried Carl, "yah, so helup me! Vat you t'ink oof dot?"
Carl was right. There were footprints in the damp sand, together with other marks, which proved that a boat had grounded and been drawn up on the shore.
"Some one has paid this island a visit," said Matt, "and not very long ago."
"No doubt of it," averred Dick. "That boat must have put in here some time yesterday. Where did the men come from and where did they go?"
He tried to follow the footprints up the knoll, but they faded out before he had got half a dozen yards from the edge of the water.
"There were three men," said Matt, studying the marks, "and they landed, stayed a little while, and then shoved off again."
"But what did they stay for?" queried Dick; "what brought them here?"