eaton, in instant apprehension.

"Got to, sir. It's the law of the ocean in a deep fog."

"But it signals our location to the enemy on the drab boat."

"If it keeps the seventy-footer within sound of our horn all the
time," laughed Halstead, "so much the better. Then the Drab will be
within range of our marine glasses when the fog lifts."

"It shows those rascals the direction of our course, too," cried
Seaton, in a still troubled voice.

"We've got to observe the law, sir, even if _they_ do break it," Tom
gently urged. "That other boat's people have been acting like pirates
all along, but that would be no excuse for us. What if we cut into a
lumber-laden schooner, and sank her at once?"

Mr. Seaton was obliged to nod his assent.

"It's a fearfully tough piece of luck for us, this fog," Tom
continued, feelingly, "but we've got to make the most of it."

"And, if Anson Dalton gets aboard any Brazil-bound steamer while we're
in this fog, the whole great game for myself and my friends is lost,"
faltered Seaton.

"If that steamer has a wireless installation," retorted the young
motor boat skipper, "then we've every chance in the world to reach her
before the Drab possibly can. Joe will hear her wireless two hours or
more before the other fellows can hear or locate a fog-horn."

"It's--it's a dreadful uncertainty that this fog puts upon us,"
groaned the unhappy charter-man. "Dalton may take advantage of this
white shroud to run straight for the nearest post office and mail the
papers that he stole."

Captain Tom's mildly warning look checked Mr. Seaton ere he had time
to say more in the hearing of Hepton.

"If you'll come aft, sir, we'll talk this over," suggested Halstead,
in a low voice.

"Gladly," murmured the charter-man.

"Now, then, sir," almost whispered the motor boat skipper, as he and
his employer stood on the deck aft, "you've written out a duplicate of
the papers that were stolen."

"I have the duplicate set in an inside pocket," responded Seaton,
tapping his coat.

"Are you ready to chance the mailing of them?"

"It's--it's a fearful risk, a terrible one, even to think of sending
such priceless papers by registered mail."

"At least, sir," urged Tom, "you would be sure the documents were
properly started on their way."

"Yet with no surety that they wouldn't fall into wrong hands at the
other end," shuddered Seaton.

"Then, since your life would undoubtedly be the forfeit if you
attempt