into the lives of
himself and his two chums, Jack Hampton and Bob Temple, during their
summer vacation the previous year. All three boys were sons of wealthy
parents and lived on country estates at the far end of Long Island.
Jack's mother was dead. Frank who was an orphan, lived with the
Temples. All had attended Harrington Hall Military Academy, but Jack,
a year older and a class ahead of his chums, had graduated the
previous spring and already had spent his Freshman year at Yale.

The previous year Jack had gone to New Mexico with his father, an
engineer, who was then superintendent in charge of field operations of
a syndicate of independent oil operators. Mr. Hampton had been
captured by Mexican rebels, and rescued by the boys, for Frank and Bob
with Mr. Temple had joined Jack after his father's loss. Later Mr.
Temple had taken the boys on to San Francisco with him, and there they
had become involved in the plottings of a gang of Chinese and white
men, smuggling coolies into the country in violation of the Exclusion
Act.

It is not to be wondered at that Frank, dreaming of those adventurous
days as he lounged in the doorway, felt a twinge of regret at what
promised to be a dull vacation by comparison.

It was true, he thought, they had everything to make them happy and
keep them interested, however. Here was the powerful radio station
built by Mr. Hampton under government license to use an 1,800 meter
wave length, for purposes of trans-oceanic experiment. Then, too,
Frank and Bob jointly owned a powerful all-metal plane, equipped with
radio, and adapted for land or water flying. Besides, there was the
new and powerful speed boat bought for the three of them this summer
by Mr. Hampton and Mr. Temple.

And their homes were admirably located for vacationing, too. On the
far end of Long Island, miles from another human habitation, with
dense woods, miles of lonely beach, and the open sea--all at their
command. Well, Frank thought, after all it might not be so exciting a
summer as the last, yet the three of them ought to be able to have a
pretty good time.

An exclamation of anger from Jack caused Frank to face about. His chum
had taken the receiver from his head.

"That interference again?" asked Frank.

"Yes," replied Jack, rising and joining his chum in the doorway. "Oh,
there comes Bob," he added, pointing to a tall, broad figure swinging
over the top of a low sandhill from the beach.

Frank's glance follo