away without some explanation of the
puzzle.

"Why, don't you understand?" said Jack, as he busied himself with the
motor. "A big fish, perhaps a wandering shark, has fouled the anchor
rope, and getting badly rattled, has put off at full speed, dragging
the boat after him. He's headed for the nearest inlet at this very
minute; but we'll beat him at that little game, won't we, George?"

Then the rattle of the motor sounded, and immediately the _Tramp_ set
off in the wake of the runaway motor boat.

A more surprised lot of boys it would have been difficult to find than
those thus left upon the little sandy beach on Cedar Island. They
stared after the two boats, and then turned to look at each other.

"Well, did you ever?" gasped Nick.

"Beats Bannigher, so it does," declared Jimmy, though it could be seen
that a humorous expression had taken the place of that look of fear on
his freckled face.

"A shark got mussed up in the anchor rope, and then set out to steal
the whole outfit!" remarked Herb. "Well, of all the funny things,
don't that take the cake, though?"

"That silly old boat of George's seems to me is always cutting up some
sort of capers. She's the toughest proposition ever," Josh declared.

"That's what I'm saying all the blessed time," grunted Nick,
unconsciously beginning to feel of his various joints, as though the
mere mention of the _Wireless_ made him remember his aches.

"But can they overtake the measly thing?" Josh asked, watching
nervously to see if he could determine how the race was progressing.

"Just because the _Wireless_ is the faster boat, don't think Jack isn't
going to run her down, hand over fist," declared Herb. "Already he's
gaining on the other. You see, the shark isn't used to towing a boat
like that at race-horse speed. And then the anchor bothers him some, I
bet you."

"Will George shoot the monster--for I take it a shark must be of pretty
good size to run away with a motor boat like that?" Josh inquired.

"Watch and see what happens. George has his gun in his hands, and
seems to be looking over, as if he'd just like to shoot; but pshaw! the
shark will stick to the bottom right along, and he can't be touched."

It was evident to them all that unless some other line of action was
brought into play the pursuers would have a pretty hard time of it
outwitting the thief that refused to show himself near the surface.

But they knew Jack would be equal to any occasion