The Separation — K.A. Applegate

We can't tell you who we are. Or where we live. It's too risky, and we've got to be careful. Really careful. So we don't trust anyone. Because they find us ... well we just won't let them find us.

The thing you should know is that everyone is in really big trouble. Yeah. Even you.

Rachel is falling apart. Literally. Her newest morph has the ability to regenerate its limbs, but when Rachel demorphs there's a lot more Rachel than when she started out. One more Rachel, to be exact. Rachel is an okay person to have around. But two could be considered overkill. Especially two Rachels with completely opposite personalities: one is pathetically weak; one is super strong and super nasty.

Now the Animorphs have to figure out a way to put Rachel back together again. Because if it's up to the "twins," Rachel the weak will surrender to Visser Three. Rachel the super bold will try to single-handedly take him down. And twice the trouble may be twice as much as the other Animorphs and Ax can handle. . . .