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. When he discovers an important Yeerk secret, Tobias knows he has to do everything in his power to destroy it. But to do so, he'll have to contend with a part of himself that's wrestling for control. A part that isn't...

Marco has never wanted to be an Animorph but the Yeerks are about to do something that will change his mind.

Cassie believes her strange dreams are just a side effect of having been given the alien power to morph into an animal, but when she learns that Tobias has been having the same dreams about the ocean, they realize someone is issuing a call for help.

When Jake, Rachel, Tobias, Cassie, and Marco stumble upon a downed alien spaceship and its dying pilot, they're given an incredible power ... a power they must use to outsmart an evil greater than anything the world has ever seen.