The Ellimist and the Crayak are to fight each other and determine the fate of the Animorphs.

What's tasty, good for you, and only takes sixty seconds to make? Oatmeal. And because of a strange reaction to the Yeerk's physiology, it's making the would-be invaders of Earth more than a little crazy. Now Rachel and the other Animorphs have a new weapon against the Yeerks. Sounds good, right?Wrong. Because using this advantage against the Yeerks has dire consequences for their human hosts. In order to avoid hurting innocent people, the Animorphs...

Rachel is captured by David, the sixth Animorph who was once trapped and left on a deserted island. He's back and wants revenge.

The Yeerks aren't playing around anymore. They're no longer hiding behind a silent invasion. And one of the first steps in their new plan is to take over the National Guard, to prepare for all-out war against humanity. Marco and the other Animorphs couldn't be less prepared for this news. The Yeerks know who they are, forcing them to hide to protect their families. Things are falling apart, and for once Jake may not be able to make the decision that...

Cassie and the other Animorphs have a few little problems. A few very little problems. Actually, the problems call themselves Helmacrons. They're less than an inch tall, and they're pretty upset at Cassie. They believe she stole their ship. Cassie thought it was just a toy and gave it to charity. Now the Helmacrons want it back. So the Animorphs have a new dilemma. Because the Helmacrons have their own secret weapon: They can shrink other beings...

Cassie's had it. After the last mission, she realizes she's getting tired of missions. Tired of battles. Tired of being an Animorph. She decides that she just can't do it anymore. So she quits.But the war for her planet isn't so easy to quit. It seems a human-Controller named Karen followed Cassie after the last run-in with the Yeerks, and she knows Cassie has the ability to morph. If she exposes Cassie, it's all over. No more Cassie. No more Animorphs....

Rachel and Ax must evict the tiny alien Helmacrons from Marco's head and prevent them from stealing the morphing cube.

The Animorphs have to make the most important decision they've ever faced: Do they continue to fight the Yeerks in secret, or is it time to let everyone know there's a resistance? That the Animorphs exist and Earth does stand a small chance against the invasion. Jake knows that either choice is a major one, not something that a kid should be responsible for. But he's getting tired of the pressure. Even though he realizes his friends need him to...

A caterpillar learns to be patient while trying to metamorphosize.

A single Arn, Quafijinivon, the last member of the race that created the Hork-Bajir has survived. He has seen his entire people wiped out. He has seen the Hork-Bajir enslaved. Now, after a lifetime of planning and plotting, he wants to get his revenge on the Yeerks. And he wants to atone for the problems the Arn have caused. He is old and weak. But he has something the Yeerks have reason to fear: the Ixcila, the mind pattern and persona of Aldrea-Iskillion-Falan....