Almost nothing could be as bad as finding out your mother is Visser One, the most powerful leader of the Yeerk invasion of Earth. But it happened to Marco. And even though he's been handling it pretty well, he knew there'd come a time when he'd have to face her again, knowing that the Yeerk in her brain has taken his mother away.So when Marco and the other Animorphs discover that Visser One is overseeing a secret underwater project, they know they have to check it out. But Marco's not sure if this is a battle he'll be able to fight.

When Marco and the other Animorphs investigate Visser One's secret underwater project, Marco finds out that his mother is his worst enemy -- the leader of the Yeerk invasion of Earth.

Marco, the other Animorphs, and Ax discover that Visser One is overseeing a secret underwater project which may be dangerous.

Almost nothing could be as bad as finding out your mother is Visser One, the leader of the Yeerk invasion of Earth. But it happened to Marco. And even though he's been handling it pretty well, he knew there'd come a time when he'd have to face her again.

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.

Tobias has gotten used to his new life. He's a red-tailed hawk with the mind of a kid. It was difficult when he first became trapped in his morph, but he's started to come to terms with things. After all, how many kids actually get the chance to fly?But now Tobias is about to make a very difficult choice: a choice that the other Animorphs know nothing about. And it could mean the difference between living the rest of his life as a hawk...and being human.

Her human name is Eva. There was a time when she had a loving husband and a son, Marco. When she had a wonderful career. But that was before she was infested by Edriss 562. Before the invasion of Earth. Now, Edriss 562 lives in Eva's head and controls her every movement. And through Eva, Edriss has become the highest-ranking general in the Yeerk empire, surpassing even her arch rival, Visser Three. She is Visser One.But it has become known that Visser One's tactics for attaining her current position were less than acceptable -- even to the Yeerks. Now she's on trial for treason. If she's found innocent she'll continue to rule. But if she's found guilty, she'll lose her life -- and possibly the life of her host, Eva. Which will mean that Marco will never, ever see his mother again...