The Sky Wagon droned through Caribbean skies, following a compass course that led to Charlotte Amalie, capital city of the Virgin Islands. With eager interest, the four people in the small plane watched the blue water below. In a few 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."