"I only found one," he called back. "I don't believe there are enough in this cove to bother about, no matter what those fishermen said."

"Did you dig deep enough?" Scotty asked.

"As deep as I could without a shovel. The mud is two feet thick down there."

"Well, you might as well come aboard. I guess if we're going to have clam chowder, we'll have to buy clams from a commercial boat."

Scotty wouldn't invite him aboard if there was any danger, Rick knew. He accepted the hand Scotty held down and got aboard.

He surveyed the situation quickly. There was no sign of any danger.

"Pretty murky down there?" Scotty asked.

"Like swimming in ink."

"We'll try again out in deep water. It should be clear near the river mouth."

"Suits me," Rick said. "I never did think we'd find clams in this cove.

The mano boats dredge in deeper water than this."

"Maybe the fishermen didn't want us stirring things up where they clam.

Come on in and I'll fix you some coffee. I made it while you were down below."

"Okay."

Once inside the cabin, Scotty said softly, "Two men. On the sh.o.r.e. One is the bodyguard. I've never seen the other one before. Both of them have rifles."

Rick considered. "They couldn't possibly know the thing--whatever it is--dropped in the water here. Or could they?"

"I don't know. Anyway, they're suspicious. Did you find anything?"

"Just as you signaled. How did you signal, by the way?"

"With the mop pail. Four taps with the bottom on the water surface. Then I filled the pail and began swabbing down."

Rick nodded. "I don't know what I found. A cylinder, maybe two inches in diameter, maybe less. Smooth. I got the fish line around it and carried the line to the sh.o.r.e. We'll have to come back later."

"We certainly will." Scotty's eyes sparkled. "But for now, let's up anchor and get out of here."

"How about the stake with the rope on it?"

"The tide's still coming in. It will be completely under the water at high tide. We'll have to avoid it, and warn Harris if we don't get back tonight."

An idea was beginning to form in Rick's mind. "Okay," he said. "Let's get going."

Within minutes the houseboat was on its way out of the cove, the two boys acting normally, as though no one was observing their departure.

Rick saw no one on sh.o.r.e, and not until they were sunward from the cove entrance did he see the sparkle of sunlight on binocular lenses. Scotty had been right, as usual.

CHAPTER XII

Night Recovery

On the way back from the airport, Steve Ames listened intently to the report of the day's activities, but delayed comment until supplies had been purchased, and a dozen eggs turned into an omelet that a French chef might have praised.

Rick was eager to discuss the whole affair with Steve, but the young agent was adroit at fending off questions without being rude, and finally the boy gave up.

Over after-dinner coffee, Steve smiled at both of them. "End of today's lesson in patience, which is one virtue neither of you has developed sufficiently. Okay, where are those two pictures?"

Scotty whipped them from the breast pocket of his shirt and handed them over without comment. Steve studied them for long minutes, then went to a table and took a magnifying gla.s.s from the table drawer. He placed the pictures directly under a lamp and studied them with the aid of the magnifier.

"It _is_ Thomas Camillion," he said finally. "Your friend Sandy Allen has a sharp eye. I wouldn't have known him, either."

That surprised Rick. Steve had never met the owner of Calvert's Favor, but because of Camillion's notorious reputation, Rick had been certain that Steve would recognize him on sight.

Steve saw the expression on Rick's face. He grinned. "You disappointed?

First of all, my knowledge of Camillion is not greater than yours. I've never seen him in person, or had any reason to study him. Crime isn't JANIG's business. Second, one expects to see a duck near water, or a squirrel near a tree. Criminals are generally found near centers of crime. They're not common in historic mansions, far from large population centers, so one doesn't expect to find them there. My reasons for not recognizing Camillion, without Allen's identification, are exactly the same as yours."

"It's just that we expect you to know everything," Scotty said half-seriously.

"Then I'm glad you're learning better. Joking aside, it's interesting that Camillion should be here. It's even more interesting that his sidekick is a crooked electronics engineer or scientist. When you add flying stingarees to that combination, it totals up to something novel in criminal ideas. But what?"

"We thought you might have an idea," Rick prodded.

"Yes and no," Steve said ambiguously. "What ideas do you have?"

Rick stared at him accusingly. "Are you holding out on us? Do you know something we don't?"

"Not yet," Steve said, and grinned at their expressions. "I mean that literally. I think I may possibly know something, but the evidence isn't in yet. It's that computer run I mentioned. We should have the results tomorrow."

"All right," Rick said. He knew better than to push Steve for more information. The agent went in for speculation only when it served a purpose. With only a hint of evidence, he avoided guessing until the evidence had been checked out. "We figured out that the flying stingarees probably are balloons," Rick reported, recapitulating their conclusions of the previous evening.

Steve nodded approvingly. "Very good reasoning. Now connect up an electronics crook, Camillion, and that peculiar antenna."

"The balloons carry radio equipment," Scotty said promptly. "The antenna picks up their signals."

Steve nodded again. "That's reasonable. Now, why do the balloons carry radio equipment? And why are they launched?"

"We're like a dog chasing his tail," Rick said with a grin. "We're not getting anywhere, but we're covering plenty of ground."

"Maybe we are getting somewhere," Steve corrected. "You found something today that may be the balloon payload. You also found out that people from the mansion were interested in your activities, but didn't want to be seen. It's obvious that the object you found must be recovered.

You've got a plan. I'm sure of it."

"We do," Rick agreed.

Scotty added, "First of all, we have to warn Orvil Harris. If he goes crabbing in the middle of the night, he might foul a prop on the stake we left there."