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This article is written from a Real World point of view.

"Recently the Yeerks have gotten control of subway trains and six or seven lines of tracks. We figure they did some simple construction that now leads the tracks right into the pool complex. We've seen them herding people at gunpoint down into various subway stations and onto trains. From there, the people are shipped off for infestation. We need your explosives to blow up the pool complex."
Jake to Captain Olston of the National Guard

The Sacrifice, published in March 2001 and written by Kimberly Morris based on an outline by K.A. Applegate and Michael Grant, is the fifty-second book in the Animorphs series. It is the tenth book narrated by Ax and his sixth and final book as sole narrator.


Official Description

The war between the Yeerks and the Animorphs is still raging. There are no more secrets - but there are plenty of lies. The kids are fighting harder than they ever thought they could. And they’re about to make the biggest decision they’ve ever had to face. A decision that may eventually break them all.

Ax and the Animorphs have known that the ultimate destruction of the Yeerk pool will give them a huge chance to take back Earth. And they've figured out a way to do it. But there’s no way to destroy the pool without destroying everyone else that may be there. And there’s no more time to think about it. There’s only yes or no...

Plot Summary

To be added



Supporting Characters:


Other Characters:



Major/Highlighted Events

  • After discovering that the Yeerks are forcing multiple humans at gunpoint to embark on subway trains and have created train lines that lead directly to the heart of the Yeerk pool, Marco suggests hijacking one of the trains and filling it with explosives, using the train as a battering ram in order to destroy the entire Yeerk pool.
  • Cassie reveals to the rest of the group that she intentionally let Tom escape with the morphing cube, causing Ax to develop an intense hatred for her, likening her to Seerow and believing her to be more dangerous than Rachel, due to her kindness; Ax's hatred temporarily extends to the other Animorphs when he realizes that they are quick to forgive her treachery.
    • Cassie privately informs Ax that her actions might be a blessing, since the Yeerks could use morphing to acquire new bodies rather than infesting hosts.
  • Ax has been secretly communicating with the Andalite fleet using the Z-space transponder, where he receives orders to prevent the other Animorphs from destroying the Yeerk pool; the Andalite fleet wishes for the Yeerk Empire to seize control of Earth and divert the majority if not all of their forces to the planet, at which point the Andalite military fleet would quarantine the planet, Ax instantly realizing that a 'quarantine' would result in the Andalites destroying Earth from orbit. Ax, after some reflection in which he remembers that Elfangor had broken Andalite military law and trusted the humans, decides to maintain his faith and loyalty in the Animorphs as opposed to the military fleet, and disobeys the Andalite military's orders.
  • The six core Animorphs, the seventeen Auxiliary Animorphs, Toby Hamee and a handful of her Hork-Bajir warriors, coupled with the Animorphs' parents, infiltrate a National Guard base, where they begin to steal explosives. The group is stopped by Captain Olston. Rachel's mother Naomi, who represented Olston's son, convinces Olston that the governor's report was not a hoax and that Jake is the leader of the resistance, and upon realizing that his superior officer is a Controller, Olston gives Jake the support of his team. Olston and his team, along with the Animorphs and James' team, subdue the Yeerk guards at a subway station. When the guards shoot some of the morph-capable-Controllers, most of which are in wolf morph, Ax fears Cassie is among the dead and realizes that he does not hate her after all, and is content when he realizes Cassie is alive.
  • Marco speaks to Visser One (Esplin 9466, formerly known as Visser Three) for the first time, becoming the last Animorph to personally engage in conversation with the visser.
  • The Animorphs destroy the entire Yeerk pool complex under the city, along with most of the Downtown district, resulting in multiple human, Hork-Bajir and Taxxon casualties and giving the Animorphs' their greatest victory thus far.
  • Ax discloses that the human Animorphs are of high school age right now, giving a direct indication to the degree of time that has passed since they joined the Andalite-Yeerk War, as the Animorphs were stated to be in middle school in The Invasion, with Rachel adding in The Solution, which took place many months after The Invasion, that they weren't in high school yet.


Morpher Morphs acquired Morphs used
Jake -- Peregrine Falcon, Flea, Siberian Tiger
Rachel -- Bald Eagle, Great Horned Owl, Hork-Bajir (Jara Hamee), Flea, Grizzly Bear
Tobias -- Human (himself)
Cassie -- Osprey, Flea, Wolf, Cockroach
Marco -- Osprey, Silverback Gorilla (Big Jim), Flea
Ax Raccoon Northern Harrier, Raccoon, Human (Main), Cockroach
Visser One -- Unnamed Octopus Creature
James Peregrine Falcon, Red-Tailed Hawk (Tobias) Peregrine Falcon, Lion, Red-Tailed Hawk (Tobias)
Collette -- Crocodile
Kelly -- Bull
Timmy -- Bobcat
Morph-capable-Controllers -- Peregrine Falcon (x6), Rhinoceros, Polar Bear, Cheetahs, Wolf (x7), Unnamed Birds, Rats


  • The cover quote is, "Everyone has nightmares. But what happens when the nightmares are real?"
  • The inside cover quote is, "Ax has a secret...."
  • This is the last book to be ghostwritten, with the final two books in the series once again written by K.A. Applegate and Michael Grant.
  • Ax makes a few references to the events of previous books, citing that the Animorphs had destroyed a Kandrona source more than once (The Stranger and The Extreme) and had destroyed a Yeerk pool (The Prophecy), as well as giving Aftran morphing powers and her subsequent decision to become a humpback whale nothlit (The Sickness). Ax also mentions the incident on the USS George Washington with Visser Two that nearly started World War III (The Deception) and, while landing on a moving subway train, remarks that he had landed on a moving vehicle before (The Experiment).
  • James is revealed to have a red-tailed hawk morph, having acquired Tobias. This marks the twenty-sixth and final time that an Animorph is acquired and the sixteenth and final time that Tobias is acquired, as well as the fifteenth and final time that Tobias is acquired in his red-tailed hawk form.
  • Rachel kills several morphed human-Controllers, marking the second time where an Animorph has intentionally and explicitly taken human life.
  • ANIBASE: A very interesting editorial mix-up occured with this book. In the manuscript for #50: The Ultimate, one of the new Animorphs, an Asian boy with a speech disability who was confined to a wheelchair, was named Tuan. Sometime before the manuscript became a book, Tuan's name was changed to Timmy. The manuscript for this book, however, was written before the name was changed, and Tuan ended up appearing in this book anyway. Don't be fooled -- Timmy and Tuan are the one and the same!
  • This is the last book published in the Italian translation, since the Italian editor Mondadori falsely declared that the last two books "they added nothing to the ending" (despite the fact that it is clear, at the end of volume number 52, that the story is still ongoing), and ended being translated by fans and released for free on a fansite.


  • On p3, Ax states that while "Aximili-Esgarrouth-Isthill" is his real name, the other Animorphs have been using fake first names the whole time to avoid detection. However, this was a ghostwriter addition that is not canonical, as the next two books (The Answer and The Beginning), which were not ghostwritten, reveal that they had been using their real first names the whole time.
  • Controller is spelled as "Contoller" on p8.
  • Ax states, both on p9 and on p65, that Elfangor gave the morphing cube to the Animorphs before he died, despite the fact that the morphing cube was left behind at the Abandoned Construction Site after his death and was not in the Animorphs' possession until they retrieved it from David in The Discovery.
  • Timmy is referred as Tuan due to an editorial oversight.
  • The Council of Thirteen is referred to as the "Yeerk High Council."
  • Despite not being in morph, on pages 42 and 43, Marco and Jake have some of their lines written as if they are using thought-speak.
  • Ax has some lines written on p69 as if he is saying them verbally, although he is in Andalite form.
  • Elfangor is once again erroneously referred to as a "War-Prince" on p72; his rank at the time of his death was that of "Prince".
  • Ax gets out of the truck twice, on p101.
  • Ax's conversation with Jake is written with quotation marks, although Ax had demorphed at that point and no mention was made of Ax morphing back to human.


U.S. Images

International Covers

Main Series #1 The Invasion | #2 The Visitor | #3 The Encounter | #4 The Message | #5 The Predator | #6 The Capture | #7 The Stranger | #8 The Alien | #9 The Secret | #10 The Android | #11 The Forgotten | #12 The Reaction | #13 The Change | #14 The Unknown | #15 The Escape | #16 The Warning | #17 The Underground | #18 The Decision | #19 The Departure | #20 The Discovery | #21 The Threat | #22 The Solution | #23 The Pretender | #24 The Suspicion | #25 The Extreme | #26 The Attack | #27 The Exposed | #28 The Experiment | #29 The Sickness | #30 The Reunion | #31 The Conspiracy | #32 The Separation | #33 The Illusion | #34 The Prophecy | #35 The Proposal | #36 The Mutation | #37 The Weakness | #38 The Arrival | #39 The Hidden | #40 The Other | #41 The Familiar | #42 The Journey | #43 The Test | #44 The Unexpected | #45 The Revelation | #46 The Deception | #47 The Resistance | #48 The Return | #49 The Diversion | #50 The Ultimate | #51 The Absolute | #52 The Sacrifice | #53 The Answer | #54 The Beginning
Megamorphs The Andalite's Gift | In the Time of Dinosaurs | Elfangor's Secret | Back to Before
Chronicles The Andalite Chronicles | The Hork-Bajir Chronicles | VISSER | The Ellimist Chronicles
Alternamorphs The First Journey | The Next Passage
TV Tie-Ins Meet the Stars of Animorphs
Graphic Novels #1 The Invasion | #2 The Visitor | #3 The Encounter | #4 The Message | #5 The Predator | #6 The Capture