done. Dave's own ship was then signalled and located by
whistle, and the launch started on its return.

"Keep that captured crew under strict guard. Don't give them any chance
to recapture their vessel!" was Dave's last warning to Ensign Burton.

The "Olga" quickly faded away in the fog and then the "Grigsby" was
picked up and boarded.

"Great work, sir, I'd call it!" declared Lieutenant Fernald, when he
heard the details of what had taken place.

"The scoundrel, to sail as a neutral, and do such dirty work for the Huns
for mere pay!" uttered Dave, indignantly. "Fernald, do you know that
there were moments when I had to restrain myself to keep from kicking
that scoundrel about his own deck?"

"I can understand the temptation," nodded the executive officer.

"On second thought, though," Darrin continued, "the skipper is certainly
being much worse punished by the suspense of mind in which his present
plight places him. He knows that, if convicted, the finding of the court
will be 'piracy,' and he knows the punishment for that crime."

"It used to be hanging," nodded Fernald. "It seems almost a pity that
this war has introduced the swifter and more merciful punishment of death
by shooting."

"And as he looks around at his crew he knows that they must face the same
fate with him, and he knows, too, that they know that he has brought the
penalty upon them."

"But is it possible that the crew were ignorant, or most of them
ignorant, of what he was doing in addition to really carrying wood pulp
cargoes?" asked Fernald.

"That will be another question for the court-martial to decide," Darrin
answered. "It doesn't seem possible that any member of the crew could
really be in ignorance of the mine-laying work."

A long blast from either the invisible "Olga" or the equally invisible
mine-sweeper now announced that the prize was proceeding on her way. The
"Grigsby" did not answer, for on a sea infested by hidden enemies it was
not wise to use too many whistle signals.

The "Grigsby" now returned to her course and former speed, and again
started on her way. Barely ten minutes had passed when from a bow lookout
came the sharp hail:

"'Ware submarine, dead ahead, sir!"

Sharp eyes, indeed, that had made out the presence of the enemy craft by
sighting the slender, almost pencil-like periscope that projected some
few feet above the water.

At the instant it was discovered the periscope sank down below the
surface.