Prologue:
My name is Darren. I guess you're probably wondering what my last name is…Well, you're just going to have to live with one name, because I can't tell you my surname, on the grounds that it will expose me and my friends to the greatest threat on the planet, the Yeerks. And telling you my last name could put my family in danger: my parents, my cousin, my dog…pretty much everyone and anyone close to me. So, for now, know a few things: my name is Darren, and the planet is undergoing a secret alien invasion. And not for the first time either…
This is where my story gets very complicated, very convoluted, and very fast. You see, the Yeerks have already made an attempt at enslaving the human race. And, you know what? They almost succeeded, too. Had it not been for the Animorphs—some five or six kids who were given access to alien technology that allowed them to become actual animals—the Yeerks would have taken the planet in less than a year. They had already enslaved the entire Hork-Bajir race—their home planet is under the complete control of the Yeerk Empire. And the Taxxons have willingly given themselves over to the enemy, just for a few scraps of meat—can you believe it? And it's not too difficult either, not for the Yeerks.
The Yeerks are not much to look at in their natural forms: just your basic grey-green slug. They're not much bigger than two inches, and about as threatening than a wad of chewing gum. But once they get to your brain, that's when you should be scared. Once a Yeerk slithers through your ear canal and wraps its putrid little form around the center of your very being, it takes over your life. You lose everything—your body, your freedom…You can't eat, speak, or sneeze, but the Yeerk can. And you just become a passive observer; trapped in your own body. And nobody can even tell the difference, because the Yeerks have access to the memories of their hosts. They're able look into your past and memorize every action, every perverted little habit. They can see the things that we hide; the very secrets that we're too afraid to speak aloud. Those tiny miniscule, almost insignificant aspects of our essence are like an open book to the Yeerks. They will taunt you, insult you and make you scream for mercy. Nobody, apart from the Yeerk in your skull, can hear your screams for freedom. Only after three days, when your Yeerk is feeding in the Yeerk Pool—with the other vile little slugs—are you free to breath, to speak…to just be free. But you can't enjoy it, because you're stuck in a cramped little cell with a dozen other people; the ones they call, Controllers. Yea…those are the Yeerks.
And here's the most ridiculous part of this story: the invasion—this apparent threat to the human race—won't be made public for another five years. Right now, the Yeerks are trying to keep their little invasion a secret, so they don't have many hosts…yet. The Animorphs won't meet Elfangor—the Andalite who gave them the power to morph into other animals—for another two years. Of course, I realize how absurd this all sounds. I'm not entirely sure I understand the whole situation myself. Aaron has only told us a few of the more important details, but I'm pretty sure he's hiding a whole universe of information from me and my friends.
That's the guy who got me into this whole mess; some kid my age named Aaron. Yea, I can't tell you his last name either. Aaron doesn't have a last name. You see, Aaron was born in a lab located in the States; the product of one of the most powerful and successful corporations on the entire planet. Aaron is really a composition of D.N.A taken from some of the strongest and most intelligent people in the world—people Aaron (as well as most of the population, apparently) call "the Elite." Oh but that's not the craziest part of this story either.
Aaron is from the future…
By now, you would have walked away from me, shaking your head, thinking, "somebody just hopped off the crazy train"—which is more than understandable. Like I said, I realize how odd this all seems: kids from the future, evil aliens bent on the enslavement of the human race, test tube warriors from the year 2085…Oh, did I mention that Aaron is a military trained solider, in addition to be a licenced time-traveller? No…well, I guess I have some more things to clear up, before I start talking about me and my friends, and the night we all met Aaron.
Alright, just to review: the Yeerks are mind-stealing aliens attempting to enslave all of humanity. The Animorphs are the only ones able to stop them, and they do so by morphing into all sorts of animals—a gift from an Andalite named Elfangor. The invasion remained a secret for the better part of three years, before the Yeerks made their presence known. Within a few short weeks, and at the cost of a great many lives, the Animorphs defeated the Yeerks and saved the world.
Now, naturally the human race changed after the Yeerks were defeated. Mankind was now in contact with extraterrestrials. We allowed the Andalites access to our planet in exchange for a specific piece of their technology. Entire colonies of Hork-Bajir were established clear across the planet. And the Taxxons…well, it's a little difficult to explain the Taxxons. And, in the hopes of bettering the relationship between the humans and the Andalites, and to improve the now obsolete technology of the Homo sapiens, the Andalites started working with the humans on a few secret projects. Within mere decades we had mastered cloning, Zero-Space travel, and advanced weaponry. Within fifty years, Eden's Garden was devised, and project Adam was put to work. And within a century, we mastered time travel. And that is where Aaron comes in.