y into the
country without yielding the customary heavy duty imposed on them, there
was also being smuggled into the innumerable lonely bayous and inlets of
the lengthy coast line vast quantities of contraband in violation of the
eighteenth amendment, also batches of undesirable aliens like Chinese,
anarchists and Bolsheviks, such riffraff as Uncle Sam had been holding
off under a strict ban.

So, too, it was understood that besides the fleet of swift, small
power-boats employed night after night in this profitable game of
mocking the Treasury Department, latterly the smugglers had been
freighting their cargoes by means of airplanes that would be able to
land the contraband stuff in lonely places far back of the low coast
sections.

It was therefore a monumental task, covering a wide field of operation
and with constant peril hovering over the heads of the two adventurous
aviators who had undertaken so joyously to spread the net and draw its
meshes about the offenders.

Their preparations having been completed, they were waiting in an
isolated little bayou surrounded by inaccessible swamps and mangrove
islands ready to take off with the coming of the friendly shades of
night.

To those who enjoyed reading the preceding volume of this series of
aviation adventures, where Jack and "Perk," in order to get their
man--one of the boldest and most successful counterfeiters known in the
annals of crime--found it necessary to fly across the Mexican boundary
line and snatch their victim out of an extinct volcano crater that had
once been the fort of the fierce Yaqui Indian tribe,[1] will think it a
rather far cry for the Sky Detectives to be detailed to active duty some
thousands of miles distant, and in the extreme southeastern corner of
the republic.

So it always must be with the famous Secret Service men--their motto,
like that of our present day Boy Scouts, is "Be Prepared"; for day and
night they must hold themselves in readiness to start to the other side
of the world if necessary--China, Japan, India, the Philippines
perhaps--detailed to fetch back some notorious malefactor wanted by
Uncle Sam, and information of whose presence in distant lands has
reached Headquarters.

As a rule it was Perk's duty to see that their flying ship was well
stocked with all necessary supplies, from liquid fuel and lubricating
oil down to such food stores as they would require, even if forced to
remain for days, or a week, without co