Jake's grandfather has died. It blows the family away, especially Jake's mom. His parents decide they should all travel to his grandfather's home to help with the arrangements. In another state. For three or four days.This is a very big problem for Jake's brother, Tom. He can't be away from the Yeerk pool for that long. So Tom refuses to go -- but his father insists. Tom's Yeerk will do anything to survive. Including making his father less of a problem.Now Jake, the other Animorphs, and Ax have to find a way to protect his father without Tom discovering their secret. And without having to choose between his father's life...and Tom's.

There's a new rumor in town. Someone has discovered an item that proves life on other planets exists, and they've been hiding it on a base called Zone 91, the most secret place on Earth. Cassie and the other Animorphs already know about life on other planets. Too well. Their enemies the Yeerks will try to access Zone 91, to find out if what's there will threaten their mission to conquer to the planet. So the Animorphs decide to pay Zone 91 and the Yeerks a little visit. But what they discover is not at all what they expect.

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...

Visser Three is still trying to find a way to reach the Pemalite ship that was hidden thousands of feet below the ocean's surface. The ship contains technology so advanced that it's superior to anything even the Andalites have built. And this time, the Visser plans to find the ship so he can use the power to complete Earth's invasion.Jake and the other Animorphs acquire additional deep-sea morphs in order to stop the Visser's plan. But while trying to destroy the Yeerk ship, the kids make a startling discovery: an underwater civilization. Have the kids discovered Atlantis... or is it just another trap?

Something is very wrong with Ax. He's sick, and the Animorphs don't know what to do about it. They can't take him to the hospital. They don't know how to contact the Andalite home world. And Ax is dying.Cassie and the other Animorphs come up with a plan. But it involves finding a new way into the Yeerk pool. There's just one problem: Jake, Rachel, Tobias, and Marco all come down with Ax's sickness. And now, for the first time, Cassie is on her own...

There's been an accident. Someone crash landed a Yeerk Bug fighter, and the Yeerks have been trying to cover it up--quickly. When Tobias spots it before they get the chance, the Animorphs decide to steal the ship, to show the world that Earth has been invaded.That's when things go terribly wrong. Before they know it, Jake and the other Animorphs find themselves in another place. Another time. And there's no way home...

The Yeerks have decided to try a little experiment. They've decided that if they can develop a way to make people more "willing" to be infested, they can speed up Earth's invasion. So the Yeerks try to invent a substance that will take away the human ability to make a decision. A substance that will eliminate free will.Now the Animorphs are not only faced with trying to slow down the Yeerks' invasion, but they also have to put an end to the genetic testing on a small group of humans. This time there's only one chance to stop the Yeerks. And if anything goes wrong, it's all over...