The Test
by Katherine Applegate and K.A. Applegate
Tobias's worst nightmare has come back to haunt him. Taylor, the evil Yeerk who enslaved his brain, has returned. But this time, Taylor wants Tobias's help to overthrow their common foe: Visser Three. Should the Animorphs do the unthinkable -- join forces with a Yeerk?
Release Date:
June 30, 2000