"Insane?" Marco echoed. "Hey, that's my word. Look, we came this far."

52 "I don't care!" I yelled, surprised at my own passion. "I'm not going to be responsible for any one dying! This isn't going to work. I don't know where I am. I don't know where we're going. I don't know what to do!"

Marco laughed. "Excellent pep talk, Cassie. Now I'm really looking forward to this."

I was going to yell at him, something like, "Look, Marco, this is not a joke." But when I looked at him, I saw that his face was bulging way out, forming a long, grinning beak.

He had already started to morph.

"I'm nock koink to ..." he started to say. But his mouth no longer worked.

He was growing larger, straining his weak human legs with his weight. His arms were flattening into flippers.

"Now!" Jake said. He grabbed Marco's flipper arm. Rachel and I jumped forward and seized his legs just as they began to shrivel.

"Heave!" Jake yelled.

Marco, half human, half dolphin, tumbled backward over the railing and fell into the sea.

"Let's go," Jake said.

"Yee-hah!" Rachel said with a wild grin. She jumped up on the railing, balanced for a moment like the gymnast she was, then launched herself off in a neat swan dive.

Jake and I exchanged a glance.

"Rachel," he said, and rolled his eyes.

"She's yourcousin," I pointed out.

"On the count of three. One, two . . ."

"Ahhhhhhhhhhhhhh!" I climbed over the rail ing and launched myself as far from the steel wall of the ship as I could.

"Aaaaaaaaaahhhh!"

I fell for what seemed like a very long time.

PAH-LOOOOSH!

I hit the water feet first and plowed beneath the surface in a pillar of bubbles.

The cold shocked me. The water was like ice. And just a few feet away was the intimidating steel wall of the tanker, sliding past at what felt like incredible speed.

53 I kicked my feet and began to rise to the sur face. I've been a swimmer since I was little, but it frightened me, being this far out in water this deep. This wasn't a pool or a pond. This was the ocean. Twenty miles from land.

I broke the surface and gasped a lungful of air and a mouthful of saltwater. What had looked like a little choppiness from up in the ship felt like towering waves down here. I couldn't see any of the others. All I could see was the side of the ship.

Come on, Cassie, I told myself, morph. Do it. This is no place for a person.

There is just about nothing as helpless as a human being in the ocean. Without my ability to morph I would not have lasted an hour.

I felt the change begin as I focused on morphing. At first, I thought it would kill me. I soon had most of the weight of a dolphin, with nothing but my human feet paddling to keep my head above water. My arms had already become flippers.

A wave washed over me, leaving me sputtering from my mouth and my blowhole at the same time.

I realized I could no longer keep my head above water. I took a deep lungful and let myself sink.

As my eyes went from human to dolphin, my underwater vision improved. I could see other figures kicking and writhing in the water around me. Jake, half-changed. Rachel, almost cornplete. Marco, with a dolphin grin, looking amused.

Then, with a kick of my newly completed tail, I knew I was safe. I had made the change. I was a dolphin in a dolphin's world. The human clumsiness, the human cold, the human fear of an alien environment, all evaporated.

I was warm and in control and right where I should be.

"Everyone okay?"

One by one they answered. We had made it. Too bad this was just the easy part of the mission.

"Well, that was fun," Marco said sardonically. "Let's never, ever do it again."

"Cassie?" Jake prodded me.

I tried to relax, to let my human mind recede just a little. I needed to listen to the dolphin instincts. I needed to understand the whale's in structions. Something no human could ever do.

"Not far," I said. "We're just a few . . . urn . . . Forget it, there's no word for it. Just believe me, we're close."

"After you, Cassie," Jake said.

54 It felt strange, taking the lead. But only I knew the way. We traveled near the surface for a while. This made it confusing for me, because whales go deeper, and the world the whale saw and knew was a deeper world than I, as a dolphin, experienced.

And yet, I knew I was going in the right direction. My echolocating clicks painted murky, half- understood pictures in my mind of underwater hills and valleys and rifts. I felt currents tugging at me. I sensed changes in water temperature.

In the end, I just knew.

" Okay , everyone, get a good lungful," I said.

We surfaced, blew out the stale air, and filled our lungs with the good clean ocean air.

"Hey. What's that?" It was Rachel.

"What?" I asked her.

"Over there. It's a helicopter."

We all watched as a helicopter flew low and very slowly over the water. It was just a few hundred yards away, and with our dolphin vision, we couldn't see it as well as we might have with our human eyes.

But as it flew closer, I could see that it was dragging a cable through the water.

"Some sort of sensor," Jake speculated.

"They're looking for something in the water," Marco agreed.

" It's them," I said.

No one argued. We all knew it was true. Controllers were flying that helicopter.

The Yeerks were here.

55 Chapter 17

"Everyone take in as much air as you can," I said again. "We're going deep." We dove and swam almost straight down. Down, down, leaving the bright barrier behind.

Away from the sun. Away from the light. Away from the air that we needed just as much as humans did.

I echolocated a school of fish ahead, just below us. But we weren't there to eat lunch. We swam through the fish and still we headed down. Down until we could see the ocean floor beneath us.

We leveled off and skimmed across the ocean floor, like low-flying jets racing at treetop level. Over waving fields of seaweed. Through darting schools of fish. Over jutting extrusions, of rock, encrusted by barnacles and home to a thousand bizarre crabs and lobsters and urchins and worms and snails.

Ahead was a ridge, a sort of long, low hill. We sailed over it.

" I'm starting to feel like maybe taking a breath would be a good thing," Rachel said. "How much farther - "

We all saw it at the same time.

Saw it, yes, but could hardly believe it.

I've become used to seeing impossible things - aliens, spaceships, my own friends turning into animals. But this was just plain mind-boggling.

It was round. As round as a plate. A very large plate. From one side to the other, the diameter must have been half a mile.

It was covered by a transparent dome. Clear glass, or whatever it is the Andalites use for glass.

And within the dome, protected from the crushing force of the water, was what looked very much like a park.

A park, in a plastic dome, at the bottom of the ocean.

There was grass, more blue than green, but it still looked like grass. There were trees like huge stems of broccoli. And other trees like orange and blue asparagus spears. At the center was a small lake, crystal-clear blue water. From the water grew fantastic, transparent green crystals in shapes like eccentric snowflakes.

"Whoa," Marco said.

"Man," Jake commented.

"I s this what you expected, Cassie?" Rachel asked me.