My name is Rachel.

Her name is Cassie.

Cassie is my best friend in the world. She is like a sister to me. I love her, to the fullest extent one girl can love another while keeping everything platonic. And I know she feels the same about me.

But Cassie does not understand clothing.

"These jeans are perfect for you, Cass." I held them up for her to see. "Crawford double-front. Durable denim, so they won't wear out for a while. Black -"

"Like me?" Cassie replied with a smirk.

I rolled my eyes. "Black, so no one will notice when you come into class wearing chicken poop."

She was stalling. School let out half an hour ago, at three-thirty, and I was supposed to be home by five. She was trying to get me off track and frustrated. But I was determined. Cassie was going to walk out of this mall with no less than three new pairs of jeans if it killed me.

"Look, Mom just got me this credit card. It's got a thousand-dollar limit, and she told me to go nuts." I pulled two more, identical pairs of jeans off the circular rack.

"And as much as I appreciate you sharing your good fortune," Cassie said, "I don't need new clothes."

I snorted. Cassie's current jeans were worn through at the knees, covered in stains from God only knew what, and ended just above the top of her boots. I looked over her shoulder past her. "Tobias? Help me out here."

Tobias was standing off to the side, hands in his pockets and face directed towards the ground. That irked me. Cassie insisted that I invite Tobias to come shopping with us. Tobias was the school geek, almost as far down the high school food chain as he could get. But he was a fellow Animorph, and Cassie says we should try to be his friend, so I was trying. Maybe if he were seen hanging around me and Cassie, he would be a little less of a bully magnet.

So the least he could do was contribute to the conversation, instead of standing there looking flustered. Something about being smack in the middle of the women's section of JC Penny always makes guys act weird. Like they think they are somewhere they are not supposed to be.

Maybe it's the mannequins wearing matching underwear.

"Tobias!"

"You need new jeans, Cassie," he muttered obediently.

"See?" I handed her the jeans. "Tobias thinks so, too."

Cassie laughed and refused to take the jeans. Typical. I held them up against her hip anyway. They would fit her perfectly. I tucked them under my arm and headed for the checkout counter. Cassie and Tobias followed me.

The lady at the counter gave us a fake smile. "Find everything you need?"

"Yes, thank you," I replied automatically. I passed her the jeans, the credit card, and my school ID. As she rung me up, I watched her, seeing if I could spot anything...off about her.

You see, she might have been a Controller. A Yeerk. And the last time I had run into one, I was stuffed into the trunk of a car and driven off to be murdered. Or made into a Controller myself. Which would have been even worse.

What is a Yeerk? Glad you asked!

You see, Earth is under attack from a hostile race of aliens. A little over a month ago, a Yeerk invasion force met another race called Andalites in battle near our planet. The Andalites tried to run the Yeerks off to keep them from enslaving humanity. They failed. And ever since, the Yeerks have been running rampant all over the globe.

Why haven't you seen them anywhere? Another excellent question! It is because the Yeerks are not like you and me. They do not walk around out in the open, doing their kidnapping and murdering the polite way. Oh, no. They crawl into your head and make you do their dirty work for them.

In their natural state, the Yeerks resemble slugs. They are less than a foot long, and they are blind and deaf, and completely defenseless. They would have stayed confined to their home planet, had the Andalites not taken pity on them and offered them a path to the stars. The Yeerks had previously made do with the other, barely functioning natives of their own world, but once they met the Andalites and realized there were far superior hosts offworld, they stole an Andalite ship and went on the warpath.

How many races have they enslaved? We are not sure. There are their original hosts, the Gedds. The Skrit Na, which resemble what humans think of when we think of space aliens. Bladed, goblinoid monstrosities called Hork-Bajir. At least one Andalite. And these massive, cannibalistic, centipede-looking things we have yet to learn the names of. And now it is our turn.

What are we doing to stop them? Well, we got lucky. A survivor of the battle for Earth, an Andalite warrior named Elfangor, crash-landed near our school. My friends and I found him. He told us all about the Yeerks and gave us the power to fight them. The power to morph into any animal we touch.

And…that's about it. We can all turn into birds. And snakes. And I can be a dog.

Who's we? Well, there's Cassie and Tobias, who've you already met. And me, obviously. There's Jake, who's our leader, my cousin, and practically my little brother. And then there's Marco, Jake's best friend and everybody else's favorite pain the butt. We're the Animorphs.

It's dumb, I know. But Marco named us. Blame him.

We thought we had a chance to do some real good. You see, Elfangor left behind a disk. He told us that it had everything we needed to know about the Yeerks and how to stop them. But we can't access it. We figured out how to, um, interact with the disk, but as it turns out, intergalactic space marines or whatever are pretty big on password protection. We tried randomly guessing the password and the disk threatened to lock us out.

So we're fighting blind. We have no idea how many Yeerks there are, or how to identify Controllers. That last one has already bit us in the butt. About a week ago, while on a family outing, my cousins and I were kidnapped. Jordan went running for help, but the Controller killed my cousin Tom, Jake's brother, and took us captive. He figured out who we were, that we had seen Elfangor. Jake and I had to kill him to hide our secret.

I've been on edge ever since. Watching everyone I talk to. I can only be certain that my fellow Animorphs aren't Controllers. Everybody else is suspect. My teachers at school. This checkout lady.

My father, mother, and sister.

Even you might be a Controller.

Transaction completed, I gathered up Tobias and Cassie. I was feeling hungry, and the Cinnabon was calling me. We started making our way over to the food court. I made Cassie carry the jeans. They were hers, after all.

Tobias started lagging. "I don't have any money," he told us.

I reached out and grabbed his wrist. "Come on. I'm buying."

I almost missed the crowd milling outside the food court. Cassie stuck her arm out in front of Tobias and I and stopped us from walking through them.

"What?" I asked.

She just pointed.

I followed her finger. Cassie was pointing through the crowd at a kid about our age. He was wearing a Subway uniform, minus the hat. And his shirt was on backwards. He was standing over one of the tables in the food court. And he was doing everything he could to cram a gigantic sticky bun down his throat.

Along with the box it was served in.