"I think you are quite right, my boy," was the magnate's reply, a very different one from the rejoinder Rob had dreaded.

"I hope you don't think me presumptuous or impudent," replied Rob, "but you asked my opinion, and you know, sir, we Boy Scouts must always tell the truth. Perhaps it seems a poor return after you saved our lives, to——"

But Mr. Grant cut the boy short with a wave of the hand.

"Nonsense, all I did was to stand by and watch. If Donald had not understood those smoke signals, you might not be on earth now. But in return, I want to ask you to do something for him."

Rob nodded respectfully but said nothing. He wondered greatly what could be coming next.

"I want you to take Donald with you on this duty for Uncle Sam. The ensign here has agreed. Are you willing to make my son one of your party?"

"Are we willing?" stammered out Rob. "Why, sir, we've just been discussing what a shame it was that he had to go on a stupid old cruise—I beg your pardon, on a cruise—when real work lay ahead, and——"

But Donald had danced up to his father cheering and throwing his hat in the air. Then he rushed up to his newly-found comrades and a hand-shaking and "bear hugging" match ensued, such as is rarely seen except among lads who are real companions, bound together by a common bond.

Suddenly above the tumult Rob's voice sounded.

"Boys, let's give the cry of the Wolf Patrol!"