The Unknown

By Katherine Applegate

Subjects: Science fiction, Extraterrestrial beings, fiction, Metamorphosis, Animorphs (fictitious characters), fiction, Extraterrestrial beings, collectionID:Animorphs, Fiction, Children's fiction, series:Animorphs, Juvenile fiction

Description: Having learned that someone has discovered proof of alien life and hidden the proof on the top-secret base called Zone 91, Cassie and the Animorphs struggle to keep the evil Yeerks away from the place.