"Rachel is still reeling from the news that Earth is secretly under attack by parasitic aliens, the Yeerks. Now she and her friends are the planet's only defense -- five kids who, purely by chance, stumbled onto a downed spacecraft and were given the power to morph into any animals they touch. The team's best lead is their assistant principal, Mr. Chapman, who is the human host to a high-ranking Yeerk official. It's not much, but Rachel's always been...

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

It begins with the dreams. Cassie has been having strange nightmares of a voice calling to her from deep beneath the ocean. They're unsettling, but it isn't until Cassie discovers Tobias has been having dreams too, the exact same dreams, of a voice pleading for help -- that she decides it's time to start listening. When pieces of debris wash up on shore, marked with alien writing, the team realises they may still have allies in the fight for Earth,...