, son!" cried Mr. Swift. "And to think I told you such
a thing was impossible! Congratulations!"

[Illustration: "What Do You Think of This?"]

At dinner that evening the conversation turned mainly to the projected
flight to the West Indies. It was decided to start the next day at
sunrise, as Captain Britten had received word from Florida that his
barge had been made ready. A tug was getting up steam to haul it to the
Cuban coast.

[Illustration: "Congratulations!" Cried Mr. Swift]

"Mr. Damon can't go with us, Dad," said Tom. "His wife won't let him! By
the way," he added with a laugh, "she was looking up the names of all
his relatives--Mr. Damon said she was glad of the excuse to do so!--but
she could find none named Jones or Brown. So that definitely proves
those two fellows were fakes and that they merely pretended relationship
in order to pump him about my work."

After supper Ned went to his home to pack a suitcase, for he was to
spend the night at the Swifts' to be on hand for the early start that
was being planned. Tom spent the evening in his office studying the
latest available data on diving operations, and plotting the route over
which the party would travel to the coast of Cuba.

[Illustration: Ned Packed His Suitcase]

Immersed in his work, he at first paid but little attention to a
peculiar odor that gradually was pervading the atmosphere.

Suddenly he realized that something was wrong; a strange buzzing filled
his ears and the lights seemed to be growing dim. He started to get
up, but instead fell across his desk.

[Illustration: Something Was Wrong]

As Tom lay there motionless, a window opened noiselessly. Stealthily a
masked figure climbed in. After a hasty glance around the room, the
intruder hastened to the desk and leaned over the unconscious youth.

[Illustration: A Masked Figure Entered]

CHAPTER VII

DEEP SEA DIVING

Swiftly the masked man took a bunch of keys from Tom's pocket. With a
directness that indicated familiarity with the place, he went straight
to the rug covering the entrance to the secret vault. Throwing this
aside, he unlocked the trap door and quietly raised it. The
combination lock, which gave warning if tampered with, had not been set
for the night.

[Illustration: He Unlocked the Trap Door]

Now the intruder very carefully draped the rug over the door in such a
way that it would spread itself as before when the trap should be closed
from below. Two