It was really bad when Jake found out his older brother was one of them. It was even worse when Tobias stayed in his morph too long. But nothing compares to the horror the Animorphs are about to face. Nothing. Jake, Rachel, Tobias, Cassie and Marco have a feeling they know where the Yeerks' new base is located. And they've even figured out how to get in—how many people notice a few flies on the wall? But they never figured they might get caught. Or that Jake could fall into the Yeerk pool. That Jake could become a human controller. A Yeerk. The enemy.