ying double," muttered Alvin, "I'll
order him off the boat and never let him set foot on it again, and, if he
belongs to that gang of post office robbers, I'll do everything I can to
have him punished."

One of the most discomforting frames of mind into which any person can
fall is to see things which make him distrust the loyalty of one upon
whom he has depended. It might be Alvin Landon was mistaken and Stockham
Calvert was in reality a Pinkerton detective whose sole aim was to bring
these criminals to justice; but, as I have shown, the full truth was
still to be learned.

And Chester Haynes' feelings were the same as those of his chum. He
glanced at the man who was puffing his perfecto, and wondered who he
really was and what was to be the end of this curious adventure upon
which he and Alvin had entered.

It was a brief run out to the Sheepscot, and the _Deerfoot_ headed up the
river again toward Wiscasset. A steam launch was seen off to the left and
a catboat skimmed in the same direction with our friends. Both were well
over toward Westport, the left-hand bank, and slight attention was given
them.

The _Deerfoot_ had not reached the upper end of Barter Island when Alvin
from his place as steerer called out:

"That looks like the boat we are hunting for."

Running closer in to the right shore than the _Deerfoot_, a second boat
was visible whose similarity of appearance caused astonishment. The bows
of the two being pointed toward each other, the view was incomplete at
first, but since the speed of each was all of ten miles an hour, they
rapidly came opposite. Alvin sheered to the left, so as to make an
interval of a hundred yards between them. Chester had caught up the
binoculars and kept watch upon the launch, his companions doing what they
could without the aid of any instrument.

"It's the _Water Witch_!" said Chester excitedly.

A minute before he did so, Detective Calvert quietly slipped from his
seat to the floor, removed his hat and cautiously peered over the
taffrail. But he did not cease smoking his huge cigar, and it struck
Alvin when he looked around that his head was high enough to be in plain
sight of anyone watching from the other craft.

Mike Murphy caught the stir of the moment.

"How many passengers do ye obsarve on the same frigate? It seems to me
there be only two."

"That is all that are visible," replied Chester, holding the glass still
leveled.

"Thin they must be them two that