Things were already really weird. Fighting aliens. Battling to have Earth. And still trying to be normal. Marco, the other Animorphs, and Ax are almost used to it. But things are changing. The Yeerk invasion of Earth started out passively. Secretly. But now, everything seems to be stepped up. Even Marco's father is talking about some top secret project at his job. Something about developing Zero-space...
Marco doesn't even know whether his father is a Controller. But he does know he's not going to let the Yeerks win this one. They've already got his mother. And Marco will do anything it takes to save his father. Anything...
Contributions to the Series' Story ArcEdit
- Marco's father finds out about the Yeerks.
- Marco and his father fake their deaths and go into hiding.
- Marco kills Visser One and frees his mother.
- Visser Three becomes Visser One.
- The Animorphs contact the Andalite homeworld.
|Morpher||Morphs acquired||Morphs used|
|Jake||--||Siberian Tiger, Hork-Bajir|
|Rachel||--||Grizzly Bear, Hork-Bajir (Jara Hamee)|
|Marco||Hork Bajir (Random Controller)||Osprey, Silverback Gorilla, Ant, Cockroach, Hork-Bajir|
|Tobias||--||Hork-Bajir (Ket Halpak)|
|Ax||--||Northern Harrier, Human (Main), Hork-Bajir|
- The cover quote is, "Sometimes there's no escape. Even for the Animorphs..."
- The inside cover quote is, "Sometimes the truth won't set you free...." This is a reference to the Bible verse John 8:32 "And you will know the truth, and the truth will set you free".
- The cover morph is never actually completed in the book. Marco morphs ant partially then demorphs.
- This book was sold in a clear cellophane wrapper with a demo CD of the Animorphs PC Game Animorphs: Know the secret.
- At the end of the story, it gives a complete break from Marco's narration with the words, "We do know who they are.... and we know you, too...."
- This was the last of the 4 book covers showing Marco morphing into an insect, the first was in Book 10 The Android (spider), 2nd was Book 30 The Reunion (cockroach) and 3rd was Book 40 The Other (bee). Because of this book's cover, Marco has the most book covers showing him morphing into an insect (four total covers), no other member has had this distinction.
- ANIBASE: This book marks the beginning of the end for the series. Once Katherine Applegate decided to end the series, she decided that, rather than having all the action occur in the last book, she'd plan out a 10 book story arc that would lead up to the grand finale in the last 2 books.
- ANIBASE: Introduced in this book is Visser One's new fighting force, the Blue Band Squadron of Hork-Bajir, so named due to the tell-tale blue bands around their upper arms. They're like the body builder equivalent of regular Hork-Bajir, trained to be super strong and kill efficiently. They are led by a Hork-Bajir named Grath.
- The new Visser One morphs a Bievilerd, a creature from a planet called Ondar. It's like a living stealth bomber, entirely black with continuous delta wings, a huge mouth, and lifeless orange eyes.
- The story of the original Visser One (for whom Marco's mother was a host) finally ends here after a long arc that carried from #5, #15, #30, #35, and then finally into VISSER. This results in the former Visser Three becoming Visser One.