The thought had of course occurred to me that it might be a trap, set to spring in any of a number of ways. While I hoped my friend in the museum still had his lower jaw in place, I did not discount the possibility of an underwater ambush. In fact, I had one of the little death rods along with me, all loaded and primed. The photos had been quite clear. I did not forget. Nor did I discount the possibility of a booby trap. I would simply have to be very careful in my poking about.

While I did not know what would happen if I were spotted solo-diving with company gear. I would have to count on my ability to talk or lie my way out of it, if catching me in this breach of domestic tranquility was what the note's author had had in mind.

I came to what I thought to be the spot, anchored there, slipped into my gear, went over the side and down.

The cool smoothness held me and I did my dance of descent, curious, wary, with a heightened feeling of fragility. Toward the bottom then, with steady, sweeping movements down, I passed from cool to cold and light to dark. I switched on my torch, shot the beam about.

Minutes later, I found it, circled it, hunting about the vicinity for signs of fellow intruders. But no, nothing. I seemed to be alone. I made my way toward the hulk then, casting my light down the splintered length of the short-snapped mainmast. Small fish appeared, staging an unruly demonstration in the neighborhood of the gunwale. My light fell upon the layer of ooze at the base of the mast. It appeared undisturbed, but then I have no idea as to how long it takes ooze to settle.

Coming up beside/above it then, I probed it with a thin rod I had brought along. After several moments, I was satisfied that there was a small, oblong object, probably metallic, about eight inches beneath the surface.

Drawing nearer, I scooped away a layer. The water muddied, fresh material moving to fill the site of my excavation. Cursing mentally, I extended my left hand, fingers at full flex, slowly, carefully, down into the mud.

I encountered no obstacles until I reached the box itself. No wires, strings, foreign objects. It was definitely metal, and I traced its outline: about six by ten by three inches. It was upended and held in place against the mast by a double strand of wire. I felt no connections with anything else, so I uncovered it, at least momentarily, for a better look.

It was a small, standard-looking strongbox, handles on both ends and on the top. The wires ran through two of these loops. I shook out a coil of plastic cord and knotted it through the nearest one. After paying out a considerable length of it, I leaned down and used the pliers I had carried with me to sever the wires that held the box to the mast. Upward then, playing out the rest of the line behind me.

Back in the boat and out of my gear, I hauled it, hand over hand, up from the depths. The movement, the pressure changes did not serve to set anything off, so I felt a little safer in handling it when I finally brought it aboard. I set it on the deck and thought about it as I unfastened and recoiled the line.

The box was locked, and whatever was inside shifted around when I moved it. I sprung the lock with a screwdriver. Then I went over the side into the water, and holding on, reaching from there, I used the rod to flip back the lid.

But for the lapping of the waves and the sounds of my breathing, there was silence. So I reboarded and took a look inside.

It contained a canvas bag with a fold-down flap that snapped closed. I unsnapped it.

Stones. It was filled with dozens of rather undistinguished-looking stones. But since people generally have a reason for going to that much trouble, there had to be a decent intrinsic value involved. I dried off several of them, rubbing them vigorously with my towel. Then I turned them around every which way. Yes, there were a few glints, here and there.

I had not been lying to Cashel when he had asked what I knew about minerals and I had said, A little. Only a little. But in this instance it seemed that it might be enough. Selecting the most promising specimen for the experiment, I chipped away at the dirty minerals that sheathed the stone. Several minutes later, an edge of the material I had exposed exhibited great scratching abilities with the various materials on which I tested it.

Someone was smuggling diamonds and someone else wanted me to know about it. What did my informant expect me to do with this information? Obviously, if he had simply wanted the authorities informed he would have done it himself.

Knowing that I was being used for purposes I did not yet understand, I decided to do what was probably expected of me, inasmuch as it coincided with what I would have done anyhow.

I was able to dock and unload the gear without encountering any problems. I kept the bag of stones wrapped in my towel until I was back in my cottage. No more messages had been slipped beneath the door. I repaired to the shower stall and cleaned myself up.

I couldn't think of anyplace really clever to hide the stones, so I stuffed the bag down into the garbage-disposal unit and replaced the drain cover. That would have to do. Before stashing it, though, I removed four of the ugly ducklings. Then I dressed and took a walk.

Strolling near, I saw that Frank and Linda were eating out on their patio, so I returned to my place and made myself a quick, prefabricated meal. Afterward, I watched the sun in its descending for perhaps twenty minutes. Then, what seemed an adequate period having passed, I made my way back again.

It was even better than I had hoped for. Frank sat alone, reading, on the now-cleared patio. I moved up and said, Hello.

He turned toward me, smiled, nodded, lowered his book.

Hello, Jim, he said. Now that you've been here a few days, how do you like it?

Oh, fine, I said. Just fine. How is everything with you?

He shrugged.

Can't complain ... We were going to ask you over to dinner. Perhaps tomorrow?

Sounds great. Thanks.

Come by about six?

All right.

Have you found any interesting diversions yet?

Yes. As a matter of fact, I took your advice and resurrected my old rock-hounding habits.

Oh? Come across any interesting specimens?

It just happens that I did, I said. It was really an amazing accident. I doubt whether anybody would have located them except by accident. Here. I'll show you.

I dug them out of my pocket and dumped them into his hand.

He stared. He fingered them. He shifted them around. For perhaps half a minute.

Then, You want to know what they are, is that it? he asked.

No. I already know that

I see.

He looked at me and smiled. Where did you find them? I smiled, very slowly. Are there more? he asked. I nodded.

He moistened his lips. He returned the stones. Well, tell me this, if you will, what sort of deposit was it?

Then I thought faster than I had at any time since my arrival. It was something about the way he had asked it that put my mind to spinning. I had been thinking purely in terms of a diamond-smuggling operation, with him as the natural disposer of the contraband stones. Now, though, I reviewed what scanty knowledge I did possess on the subject. The largest mines in the world were those of South Africa, where diamonds were found embedded in that rock known as kimberlite, or blue ground. But how did they get there in the first place? Through volcanic action, as bits of carbon that had been trapped in streams of molten lava, subjected to intense heat and pressure that altered their structure to the hard, crystalline form of a girl's best friend. But there were also alluvial deposits, diamonds that had been cut free from their resting places by the actions of ancient streams, often borne great distances from their points of origin, and accumulated in offshore pockets. That was Africa, of course, and while I did not know much offhand as to New World deposits, much of the Caribbean island system had been built up by means of volcanic activity. The possibility of local deposits, of the volcanic-pipe variety or alluvial, was not precluded.