tell us
anything about what you do?"

"Sure I can. I'm not one of Steve's hush-hush crew. I'm a simple Navy
lieutenant."

Rick chuckled. "In other words, you can't tell us."

Steve said, "He's executive officer of the UDT group here. And he's
group intelligence officer. I might also add that he's brighter than he
looks."

"Then what do you make of this business?" Scotty inquired.

"I'm not that bright," Kelly replied. "Seriously, this one has me
stumped. First of all, it's easy to understand why a shadow picked you
up. After all, it must have been obvious that you knocked Steve's tail
off. So they simply picked you up instead, hoping that you'd lead them
back to Steve, or that you might be important in some way they couldn't
understand."

"It's nice to have someone do my thinking for me," Steve said. "Carry
on, Lieutenant."

"Aye, aye, Sir. The tail stuck with you. When your party split in two,
he decided to stay with you instead of Zircon and Briotti. There could
be two reasons: First, you were the ones who contacted Steve on the
street. Second, you stayed at the waterfront while the others went off
in a taxi. I like the second reason better because of what happened
later. How about you, Steve?"

"I'm with you. Go ahead."

"Well, at this point I get lost. You put on your gear and swam out, not
with any particular destination in mind, but looking for a rock or a
coral head or something of the kind where you could see fish. The shadow
watched you. Suddenly he got excited, grabbed a boat, and tried to run
you down."

Steve grinned at the boys. "In fact, he got so excited that he stole a
boat right out from under the owner's nose. What do you think of that?"

Rick scratched his head. "We'd about decided he was either desperate or
stupid. I guess he was both."

Kelly continued. "The big point is, what made him desperate? It could
only have been one thing, as I see it. You were getting close to
something, and he was afraid you'd find it. So he lost his head. That's
borne out by the remark his pal made last night, that he'd pulled enough
stupid stunts for one day."

"But what could we have been getting close to?"

"I don't know. Whatever it was, it isn't there now."

Scotty and Rick sat up straight. Scotty demanded, "How do you know?"

Steve smiled. "Because a team of Navy frogmen went over the entire area
inch by inch this morning."

At the boys' surprised looks, Kelly explained, "You told the Shore
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