The experiment / Applegate, Katherine

Psychology professor Odin Fruder, fed up with disruptive students, designs a project to keep them busy.

The Yeerk that controls Jake's brother Tom is desperate to keep Tom from going with the family to his great-grandfather's funeral, even if he has to kill Jake's father.

The Animorphs try to thwart the Yeerk plan to invade Earth by destroying the ability of people to make decisions.