ers of the submarine division, tells me that his radio receivers
aboard the boats of his fleet have picked up any number of mysterious
series of dots and dashes lately. Code experts have been working on
them, but they have proved meaningless.

"He was puzzled by them. He still is puzzled. But, we have noticed
that after every such flooding of the ether with these dots and
dashes, a shipment of liquor has appeared on the market. And one
theory advanced is that the liquor was landed along the coast of Long
Island or New Jersey in boats controlled by radio from a powerful land
station. The boats, of course, according to this theory, were launched
from some liquor-laden vessel which had arrived off the coast from the
West Indies. Radio-driven boats, automobiles or planes, Lieutenant
Summers tells me, are directed by a series of dots and dashes. So you
see, our theory sounds plausible enough, and, if it is correct, the
direction probably has come from this secret radio station."

Big Bob's brow was wrinkled in thought. He seldom spoke, but usually
when he did so, it was to the point.

"In that case," he asked, "what would be the necessity for this
radio-driven airplane? Apparently, the airplane is for communication
from ship to shore. But, with a radio land station, why can't such
communications be carried on by radio in code?"

Captain Folsom looked thoughtful.

"There is something in that," he said.

"Perhaps, these plotters are playing safe," suggested Frank. "They may
figure that code would be intercepted and interpreted. Therefore, they
confine their use of radio to the transmission of power waves, and do
not employ it for sending messages. The airplane is the messenger."

Jack nodded approvingly.

"Yes," he agreed, "Frank's idea is a good one. Besides, by using a
radio-controlled plane, the plotters can scout over the surrounding
waters for miles whenever a ship is about to land a cargo. The plane
can make a scouting expedition over the shore, too, for that matter.
You see a radio-controlled plane has an immense advantage for such
scout work, inasmuch as it proceeds practically without noise."

Captain Folsom slapped his knee resoundingly with an open palm.

"By George," he cried, "I believe you boys have hit it. This scout
plane is the answer to what has puzzled us the last few weeks. We know
liquor is being landed somewhere from ships, but despite our best
efforts both ashore and on the water, we have been