Tony scraped a chair in the living room. Rick stayed where he was, in
case the frogmen had lingered outside. In a few moments he heard the
back door open and close, and he tensed, but it was Scotty's voice that
spoke.

"They're gone. I just wanted to make sure."

The three gathered in the living room, and Tony chuckled. "If I
associate with you two for much longer, I'll get to be the world's
champion dissembler."

"What happened?" Rick demanded.

"Simple and unlucky. The two frogmen surfaced practically under me. My
own fault, because I had moved much closer to the boat. I think one of
them almost fired a spear at me, but the other stopped him. They invited
me to go aboard, and I didn't think it wise to refuse the invitation."

"I imagine not," Rick commented grimly. "Then what?"

"Naturally, they demanded to know what I was doing. I admitted to
overpowering curiosity that got the better of my manners. They wanted to
know who I was and why I was on the island. I told them the truth, of
course, at least partly. I identified all of us. Then I'm afraid I told
a slight untruth. I said we had found reference to the _Maiden Hand_ in
an old manuscript, and were diving in hopes of finding cannon and other
old things which we planned to sell for museum pieces to pay for our
vacation. I believe they accepted my story."

"It's a good story," Scotty approved. "Just enough truth to make it ring
true."

"They've been watching us," Tony went on. "They asked why the plane had
gone, and why it had come back with only the pilot. I told them
Professor Zircon had cut himself and gotten a coral infection, and that
the doctor at Charlotte Amalie felt that he should stay there for
treatment."

"I guess they haven't recognized Scotty and me as the two who stopped
Steve's tail."

"Seems not," Tony agreed. "Well, I admitted that I was still curious
about their activities, since night diving is not common. So they told
me a story."

The boys waited breathlessly.

"These gentlemen thirst for scientific knowledge," Tony said with a
grin. "They claim an interest in ichthyology, but they know less about
fish than any cat does. Their story is that they have developed an
underwater recording device with which to make recordings of fish
noises. Since they have some evidence that certain fish make their
noises only at night, it is obviously necessary to make recordings at
night. So they dive, leave their equipment, and pick it up the next