ew moments they should pass over the island that was
their ultimate destination.

Rick Brant, in the pilot's seat, turned to the husky, black-haired boy
next to him. "See anything yet?" he asked.

Don Scott had been surveying the far horizon through binoculars. He took
them from his eyes and shook his head. "Nothing but water. You sure
there is an island called Clipper Cay?"

Rick let the plane fly itself for a moment while he stretched
luxuriously. He was a lean, long-legged boy with brown hair and eyes and
a bone-deep tan. He grinned at his friend. "No faith. That's the trouble
with you."

"No logic, that's the trouble with you," Scotty countered. "If there
were such an island it would be called an island, not a cay. A cay is
something that follows an O, as in okay."

The two scientists in the rear seat had been listening with amusement to
the boys. Since the start of the expedition Scotty had professed doubt
and misgiving, more for the sake of conversation than anything else,
Rick was sure.

Dr. Anthony Briotti, archaeologist of the Spindrift staff, leaned
forward. "At least pronounce it correctly, Scotty. 'Cay' is pronounced
'key.'"

"See?" Scotty exclaimed triumphantly. "The only place where they have
islands called keys is in Florida. We're on a wild-goose chase, I tell
you!"

Big Hobart Zircon, a nuclear physicist and long-time friend of the boys,
tapped Scotty on the shoulder. "Since you're so certain of that, may I
ask why you came?"

Scotty tried to look martyred. "Only because of the buddy system," he
said solemnly. "The first rule of underwater safety--or above-water
safety, for that matter--is that you have to swim with a buddy. You and
Tony swim together, so I had to go along as a buddy for Rick. Somebody
has to chase the mermaids away from him, and it might as well be me."

"That's nice of you," Rick said soberly. "There'll probably be a whole
horde of mermaids guarding the treasure, not to mention half a dozen sea
monsters."

Tony Briotti said, "There's one mermaid I wish were with us, and that's
Barby. After all, she started this whole thing. Too bad she has to miss
out."

Rick's pretty sister, Barbara Brant, had unwittingly launched the flight
to the Virgin Islands by getting into an argument with Tony Briotti
about the authenticity of the legend that pirates had once used
Spindrift Island as a hangout. Tony had challenged the legend. After
that, of course, proof had to be found.

Ri