"l'm guessing what we'll see is fish," I said. "The more I think about this, the more I wonder if maybe Erek was wrong. This island looks awfully peaceful."

"l don't think the Chee make many mistakes,"Cassie said. "But look, why waste time worrying about it? Let's swim!"

Cassie took off at high speed through the water, and I couldn't help but give chase. Soon the five of us were tearing around at maximum dolphin warp, leaping out of the waves, diving to the bottom only to go ripping back for the surface,

and just generally behaving like happy five-year-olds.

It was a party in the water. The water felt warm now. Warm and slick as it rushed across my smooth skin. I dove deep, holding my breath for long minutes. I skimmed just inches above the sandy bottom, then rolled over and looked up at the sun, a distant, wobbling yellow ball that jumped this way and that through the water distortion.

I fired a burst of echolocation clicks from my head and got back an amazing "picture" made up of bouncing echoes. My clicks bounced off fish, and off the shoreline, and off the rocks that jutted up from the bottom. The clicks also bounced off Ax, and the picture of his shark body disturbed the perfect happiness of my dolphin mind.

Get over it, I told myself. He's Ax, not a real shark. Forget sharks.

Put sharks out of your mind.

"0kay, let's focus a little here," Jake said, trying to impose some order on our idiot play. "Keep the shore to your left and let's take a quick run around the island."

"You mean like a race?"Tobias asked. "Be-cause that would be cool!" In my head, I heard Cassie laugh. "So, Tobias. I guess you're past your fear of the water?"

"lt's kind of hard to be afraid of anything

right now," he said. "This was worth it. This is so cool. It's like flying, but with a really thick wind. Come on! Race you!" He took off and the rest of us followed. Ax came up behind us, but he was slower. Maybe his shark brain automatically disliked dolphins as much as dolphins dislike sharks. I don't know. I didn't care. I was in a race!

Down and swim and swim, then up, break the surface to blow out old air and suck in new, then back down to swim and swim, and kick my powerful tail for every iota of speed I could get!

We were zooming madly through the water, each trying to be the fastest around the island.

I hadn't been echolocating for a while but then, as we turned a corner, I fired off a burst. The picture that came back made me stop dead in the water.

"What is that?"

"What?" Jake asked.

"Shoot some clicks," I said.

I heard everyone blasting away, machine-gun bursts of clicks.

"Whoa!"

"What is it?" Ax asked. "Are you sensing something?"

"What is that?" Cassie asked.

"l don't know, but it isn't natural, that's for sure," Tobias said.

"Let's go see," I suggested. "There are limits to this echolocation thing."

We turned away from the island and headed farther out to sea. The thing we had sensed was composed of hard surfaces and sharp edges. And it was huge.

Now our human minds were in charge again. At least mine was. Because I guess I knew this was what Erek had told us about. And if that part of his story was correct, then maybe the rest was, too. Maybe my mother was down there in that place of hard surfaces and sharp edges.

We were in deep water, maybe two hundred feet, when we reached the spot we were looking for. But there was nothing there. Nothing but waving seaweed and jutting rocks and schools of silvery fish.

I fired another echolocating burst. According to my echolocation, there was a massive underwater structure of some sort directly in front of me.

"Erek's trick," I said. "They're using the same trick the Chee use. It's a hologram. A hologram of a normal seabed. That way divers who may come around won't see it. And it won't be visible to planes flying over on sunny days."

"Yeah, but is it just a hologram, or a force field like Erek has?" Jake wondered.

"lt would take a great deal of energy to sustain a hologram that large," Ax pointed out. "To maintain a force field in water would take the energy level of a Dome ship."

"0nly one way to find out," Rachel said. "let's go." We headed straight for the place our eyes told us was just seabed. We swam for maybe fifty feet and then everything changed. It was like sticking your head through a movie screen and suddenly seeing the stage behind it.

There, less than a quarter mile from the mansion on Royan Island and two hundred feet underwater, was a pink-shaded structure built into the side of an underwater slope.

There were three vast openings, each big enough to drive a dump truck through. Two were closed by steel doors. The third was open, revealing a dark tunnel.

Between these large openings were two circular portholes covered by convex glass or plastic. I could see clearly through one of these transparent blisters. Inside there were humans working at computer workstations. It looked weirdly normal. Like any office full of engineers or whatever. A Dilbert-looking place.

Except for the fact that it was in an underwater building.

And of course there was the fact that in Dil-bert's world there aren't Hork-Bajir standing guard.

I could see two of the big aliens. Seven feet tall. Blades growing out of their wrists and elbows and knees. Feet like tyrannosaurs. Snake-like heads topped by two or three forward-raked horns. Spike-tipped tails.

Each had a Yeerk in its head. I'd met some free Hork-Bajir. They were kind of sweet, despite their deadly looks. But these were Hork-Bajir-Controllers, of course. And the humans were human-Controllers.

In the second blister window I saw nothing but a single room. In it were a desk and a couple of chairs. And nothing else.

"0kay, so this is the place," Rachel said. "Now all we have to do is figure out what they're doing here."

"l need air." I shot to the surface to blow out and refill my lungs. The others followed. All except Ax, whose gills let him breathe underwater.

We hung around on the surface for a few moments. I wanted to look around and see the normal world, I guess. Feel the air.