Jake wakes up one morning to find he is suddenly twenty-five years old, the Yeerks rule the world, all the other Animorphs are either dead or Yeerk-infested, and he alone is left to fight.

SUMMARY: The blue box Elfangor used to create the Animorphs has been found by David, but David doesn't know what it is. The Animorphs have to get that box at any cost. David ends up on the run with the Animorphs and Ax, and may become the sixth Animorph.

SUMMARY: The Yeerks are stepping up their invasion tactics. And Marco has problems of his own. His dad is starting to date. But Marco knows his mother might still be alive.

EDITORIAL REVIEW: The Ellimist has helped the Animorphs many times. He is all-powerful and has only one enemy, the Crayak. In a cosmic showdown, the two enemies choose champions to represent them in a battle to end all battles. The Crayak chooses the dreaded Howlers. The Ellimist chooses the Animorphs.

SUMMARY: 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 if 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.

The Animorphs have managed to contact the Andalite home world, but the battle is far from over. Visser Two has arrived on Earth, and he's not happy about the state of things. He decides the best way to take over Earth is to have the humans destroy each other, exhausting their weapons in the process. He's going to start World War III.Ax and his friends know that Visser Two means business. There are only two ways to keep him from destroying everything they know: Find a way to stop the war, or find a way to stop him forever...

Elfangor-Sirinial-Shamtul is an Andalite war prince—the one who gave the Animorphs the power to morph. "The Andalite Chronicles" is the story of how this warrior-cadet ended up on planet Earth Ages 9-12. Pub: 12/97.

SUMMARY: Marco hears a downed submarine. When they investigate an explosion sends them back in time millions of years.

EDITORIAL REVIEW: The Animorph kids are joined in their fight against the evil Yeerks by Ax, an Andalite who is stranded on earth until his alien pals return and who is seeking revenge against the alien who killed his brother. Original."

The Yeerks are not the only invaders of Earth. Meet the new enemy: the Helmacrons. Cassie finds their miniature spaceship and donates it to a toy drive. Big mistake. The Helmacrons are tiny, but they're far from helpless. They have the technology to shrink other creatures to their size. And until they get their spaceship back, they're taking hostages. The Animorphs must find a way to send these pests back into space -- before it's too late.

Caught in the depths of their strange new world, Mo' Steel and Billy Weir encounter a lost Remnant, Kubric DiSalvo. Unfortunately, the ship has transformed him, replacing his skin with a transparent plastic coating. Scared and awed by the ship's vicious power, the group tries to rejoin heir friends. Meanwhile, the other Remnants are in danger in another stratum of the ship: Yago and Jobs are stuck in a computer-generated sea battle. When the groups meet, Billy finds he can communicate with the ship's core. Will his strange past help him to understand ­ or even control ­ the ship in time to save everyone? While Jake and the other Animorphs try to stop Visser Three from reaching the Pemalite ship at the bottom of the ocean, they discover a strange underwater civilization.

EDITORIAL REVIEW: This series follows the story of a group of five young kids who must use their knowledge and newly acquired ability to "morph" into any animal they touch to try to save the world from invading aliens.

EDITORIAL REVIEW: In this final installment of a trilogy that began with "#20: The Discovery" and "#21: The Threat", the Animorphs must save the world leaders and eliminate the threat of David, the Animorph who could destroy everything.