“Right arm at head, left arm down in front—­that’s ‘D,’” announced Harry who was watching with the glasses.  “Then right and left both down and diagonal to the right—­that’s ‘A.’  Next both arms diagonally down away from the body—­that’s ‘N.’  Oh, he’s telling us his name—­Dan!  Hurray!  He’s introducing himself!”

“Here comes the rest,” cried Harry excitedly, “both arms diagonally downward and to the left—­that’s ‘G.’  Now the right down in front and left diagonally up and out from the shoulder—­that’s ‘E.’  Next both arms out horizontally from the body—­that’s ‘R.’  Why, that spells ‘DANGER!’ What does that mean?”

“Search me!” declared Tom.  “I’m not a bit surprised, though for we’ve been in danger ever since we left Mobile.  Anything goes here.  I’d thank him to tell us some news, though.”

“Well, here comes some more!” announced Jack who had shut off the power, permitting the Fortuna to ride the smooth waters of the little bight without headway.

“Here’s some more!” cried Arnold, who has again taken the glasses.  “Left arm over head, right arm diagonally down—­that’s ‘K.’  I learned that code last fall.  Here’s another.  Left arm up from the shoulder diagonally and right down in front—­that’s ’E,’and he repeats it.  Then right out horizontally and left straight up from head—­that’s ‘P.’  Next, right out horizontally and left diagonally up and across the breast—­that’s ‘O.’  Now the left is out horizontally, and the right down in front—­that’s ‘F.’  He repeats it.  Why, that says ‘DANGER, KEEP OFF’!  What does he mean?”

“Maybe he means what he says,” suggested Jack.  “Answer him, Tom, and tell him we’re coming ashore.  Arnold and Harry, will you get the boat overboard and we’ll go ashore to see what’s up.  Better take your automatics and see that the boat is properly equipped.”

“Right-o, Captain!” cried Tom.  “I’ll do my best.”

The boat was quickly brought around and Arnold, Harry and Jack prepared to go ashore.  As they pulled away from the Fortuna, Harry cautioned Tom to watch the plug in the after cabin and keep dry.

As the boat approached the shore the stranger on the beach frantically made signals indicating that he wished them to return to the Fortuna at once.  Putting his fingers to his lips he glanced about as if in alarm and then put out his hand in a gesture of caution.

“I’ll bet there’s some monkey business going on somewhere!” ventured Harry.  “Why should he send up smoke signals for help and then tell us to keep away because of danger.  He’s kidding us!”

“I think I can see someone running toward us through those trees and bushes over there!” announced Arnold standing and pointing.

A figure broke from the cover of the bushes indicated just as Arnold spoke.  It was the figure of a man.  He stopped a moment.

Tom from the Fortuna gave a wild cry and waved his arms.

A shot rang out and the strange boy on the beach fell forward.