Katherine A. Applegate

When Tobias and his friends were given the power to morph, they were also given an important warning: Never stay in a morph for more than two hours. But Tobias broke the time limit, and now he's trapped in the body of a hawk - forever....

The Earth is being invaded, but no one knows about it. When Jake, Rachel, Tobias, Cassie, and Marco stumble upon a downed alien spaceship and its dying pilot, they're given an incredible power - they can transform into any animal they touch. With it, they become Animorphs....

There's something pretty weird going on in the woods behind Cassie's house, the place where Ax and Tobias call home. It seems the Yeerks have figured out one very important fact: Andalites cannot survive without a feeding ground....

The battle is still raging, and it's out-and-out war. Jake and the other Animorphs have found a way to slow the Yeerks down, but now the Yeerks have decided the best way to win is to just destroy everything and everyone who gets in their way....

Rachel is still reeling from the news that the Earth is secretly under attack by parasitic aliens known as the Yeerks. And that she and her friends are the planet's only defense....

The last time Rachel and her friends entered the giant Yeerk pool beneath their town things went very bad. This time they plan to be careful, and sneak in as roaches, just to spy. Once they're inside, though, the team gets caught....

There's been an accident. Someone crash landed a Yeerk Bug fighter, and the Yeerks have been trying to cover it up - quickly. When Tobias spots it before they get the chance, the Animorphs decide to steal the ship, to show the world that Earth has been invaded....

David, the traitorous Animorph, is back. When the Animorphs decided to give another human being the power to morph, it was one of their biggest mistakes.

We never should have done it. But we needed a break. Some time off from the superhero stuff. A chance to act like normal kids. Well - as normal as four kids who can morph into animals, a boy trapped in a hawk's body, and a bright blue alien can be.

Tobias has gotten used to his new life. He's a red-tailed hawk with the mind of a kid. It was difficult when he first became trapped in his morph, but he's started to come to terms with things....

We can't tell you who we are. Or where we live. It's too risky, and we've got to be careful. Really careful. So we don't trust anyone. Because if they find us...well, we just won't let them find us. The thing you should know is that everyone is in really big trouble. Yeah. Even you.

Things were already really weird. Fighting aliens. Battling to have Earth. And still trying to be normal. Marco and the other Animorphs are almost used to it. But things are changing. The Yeerk invasion of Earth started out passively, secretly.

The Yeerks have decided to try a little experiment. They've decided that if they can develop a way to make people more "willing" to be infested, they can speed up Earth's invasion. So the Yeerks try to invent a substance that will take away the human ability to make a decision.

Dak Hamee is a unique Hork-Bajir. His people call him a seer. He learns more quickly and completely than the rest of his docile race. Hork-Bajir like him are born once a generation.

Something is very wrong with Ax. He's sick, and the Animorphs don't know what to do about it. They can't take him to the hospital. They don't know how to contact the Andalite home world. And Ax is dying. Cassie and the other Animorphs come up with a plan.

It all started with the dreams. But Cassie didn't pay much attention to them. She and her friends have been having nightmares ever since they acquired the power to morph....

Ax and the Animorphs are about to have a huge problem. It starts when they decide to morph into mosquitoes in order to slip by some unsuspecting Yeerks, and ends with them stuck in Zero-space with no idea how they got there, no way back to Earth...and no oxygen....

Rachel's got some pretty strange stuff happening. She can't control her morphing. One minute, she's doing homework. The next, she's morphing a full-grown crocodile, and - without returning to human form - she becomes an elephant....

The war between the Yeerks and the Animorphs is still raging. There are no more secrets -- but there are plenty of lies. The kids are fighting harder than they ever thought they could. And they're about to make the biggest decision they've ever had to face.

Cassie's had it. After the last mission, she realizes she's getting tired of missions. Tired of battles. Tired of being an Animorph. She decides that she just can't do it anymore. So she quits. But the war for her planet isn't so easy to quit....