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 - five kids who, purely by chance, stumbled onto a downed spacecraft and were given the power to morph into any animal they touch - are the planet's only defense. But Rachel's always been something of a daredevil. So when it's suggested that they infiltrate the home of their assistant principal, Mr. Chapman,...

Jake finds a Web site devoted to the Yeerks that could be a trap so they must move quickly.

"Tobias has pretty much gotten used to his life. He's a red tailed hawk with the mind of a kid. It was pretty weird when he first got trapped in morph. But now it's almost okay... Now Tobias is about to make a very special choice. A choice that the other Animorphs and Ax know nothing about. And it could mean the difference between being a hawk... and being human..."--Cover.

Warned never to stay in his animal shape for more than two hours, Tobias forgets when he becomes involved in a rescue campaign and faces being trapped in a hawk's body forever

"What would you do if you were the only alien trapped on a strange planet? ... as an Andalite warrior-cadet, Ax has to be pretty cool about stuff like that. He's been hanging with the Animorphs ever since the Dome ship was destroyed by the Yeerks and his brother, Prince Elfangor, was destroyed by Visser Three..."--Cover.

Cassie acquires the mind of Aldrea, daughter of Seerow, Andalite Prince, as well as her memory, persona, secrets, and an abundance of valuable information that will help the Animorphs.