Don Melville’s face was now a sickly white, but he felt that he had to act on the instant.

“Here, let that fellow go,” he ordered, darting up, his eyes blazing.

“Get back there!  Stand away!  Hands off!” roared the submarine boy, facing young Melville and sending him back by a blow in the chest.

“Let that fellow go!” insisted Don, angrily.  “If you try to hold him, I won’t be responsible for what I do!”

“I can tell you what you’ll do, if you try to mix in at all where Mr. Farnum is busy,” retorted Jack, facing his foe with a savage grin.

Nevertheless, Don, espying a stick of wood lying on the ground, snatched it up, then tried to dart around Captain Jack in order to get at Mr. Farnum, who was having a rather one-sided struggle with the recent fugitive.

But Jack stopped Don—­stopped him all of a sudden, by rushing at him and forcing him back up against a tree trunk.  Whack! thump!  It was no time for delicacy.  Young Benson struck Don two hard blows in the face, next wrenching the stick away from him.

“The ground’s good enough for you—­full length!” snapped Jack; wrathfully.  Leaping at the Melville heir once more, he bore that angered youth to the ground.  Had not Don been winded by so much running he would not have been so easy to handle.

“Now, you stay there,” commanded Jack, testily.  “I believe you know a good deal about things that have happened to me to-night, and we’ve got to get it all straightened out.”

“I’ve got this one, Jack,” called Mr. Farnum, gleefully.

The arrival of the real Jack Benson on the scene, in contrast with the sham one, had opened the boatbuilder’s eyes.  He could not fathom, yet, what it all meant, but he was certain that his hitherto trusted young captain would be able to explain it all satisfactorily.

The young stranger in blue now lay on his back, while Jacob Farnum sat astride of him.  The boatbuilder felt carefully over the outside of the clothing of his captive, until his hands encountered the feel of paper.

“I guess this is what I’m looking for,” muttered the “Pollard’s” builder, thrusting his hand into a pocket and pulling out an envelope.  “This looks like the envelope Don Melville handed you, back there up the road.  Let us see how much you got for your rascality to-night.”

Striking a match, Mr. Farnum drew some banknotes from the envelope, counting them.

“Twenty dollars, for all that dirty work,” sneered the boatbuilder.  “Young man, you sell yourself too cheaply.  It ought to be worth more than twenty dollars, just to have to be found with the Melvilles.”

Hearing that, Don gnashed his teeth.  Like many another rascal, Don wanted people to think well of him.

“Jack,” called out the boatbuilder, “see if young Melville has a long, white envelope anywhere about him.  In the inside coat pocket, if I remember rightly.”