The Warning is the sixteenth book in the Animorphs series, written by K.A. Applegate. It is narrated by Jake.

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


Official Description

Jake's made a pretty amazing discovery. It seems like there may be other people who know about the invasion. Others who know about the Yeerks. Jake finds a Web site devoted to the Yeerks. And Jake, the other Animorphs, and Ax aren't sure it's too good to be true.

But if they try to investigate the site and it's a trap, there's no way the Yeerks won't find out who they are. If they don't check it out, they'll never know if they're the only ones fighting. Whatever Jake and the others decide to do, they've got to move quickly, because Visser Three isn't the only one dying to meet them...

Plot Summary

Jake is on his computer, signing onto the internet. He checks his e-mails, one of which is from Cassie, who says he's the one for her and she must have him, but Jake obviously knew that this e-mail came from Marco, so he decides to get him back by writing an e-mail saying that he can't be involved with any girl until Marco gets one who likes him. He sends it, and just as he's about to sign off, he's gets this urge where he types into a search engine "Yeerk". Expecting nothing, Jake is amazed to see that there was one match to the word.

Animorphs warning book 16 inside cover

Inside cover

He later gathers the other Animorphs at Marco's house because Jake needed a computer and Marco's computer was better than his. He shows them the web page, which is entirely devoted to letting the world know about the Yeerks. Jake clicks on the "Types of Yeerks" page, which shows drawing of different aliens, one of which looks just like a Hork-Bajir. Marco, Cassie, and Rachel think that the page is either a mix of truth and lies, or just a coincidence. Jake then clicks onto a list of known Controllers and points to the name "Chapman". He wonders why whoever put the site together doesn't mention The Sharing, which means either they don't know about The Sharing or this is a Yeerk trap. Cassie decides that they should check out the chat room, but Jake's not sure its safe, Marco offers to hack the system, but Ax offers to encode Marco's software in a way that will make it impossible for anyone to trace them. Marco reluctantly agrees and Ax sits down and types in a code making Marco's computer hack-proof in just three minutes. In the chat room, the Animorphs watch a conversation that's going on, one person that goes by username "Chazz" talks about how serious the Yeerk threat is, while username "Gump8293" is worried because his dad maybe a Controller. The Animorphs believe this could be a Yeerk scam, but Cassie isn't so sure. She thinks there's something real about the people in the chatroom, especially Gump. Jake also has the same feeling, but Ax couldn't tell, and Marco thinks its a little of both: the web page was created by Yeerks to help them locate any humans who knows about them, while at the same time, it got a little out of the control. Jake then asks Ax to hack in and penetrate the protected screen name files, but after a few minutes of typing furiously, he is unable to get into Web Access America's central computer. Marco then comes up with an idea, they travel to WAA's main office, sneak in and get the real names behind the screen names from the main computers.

The Animorphs gather at the airport on a Saturday morning. Because it would be too far away for them to travel to and back from WAA's main office, their plan is to morph into flies and sneak on board the plane.

At Web Access America, Marco and Ax hack into the WAA records and discover the identities of some of the screen names on the Yeerk website. They need a distraction, so the children morph and create a spectacle for anyone working in the offices. One of the users from the website is the founder of WAA himself, Joe Bob Fenestre - the second richest man in the country. On the way back to the airport, Cassie objects to Jake morphing the fly again. Jake untruthfully tries to convince the others that he has no issue morphing the fly, getting him into an argument with Cassie. Their relationship is strained for the time being.

Back home, Jake needs to form a new plan to infiltrate Joe Bob Fenestre's multi-million dollar compound. Cassie objects, instead wanting to save a young child on the Yeerk website going by the screen name of Gump from confessing to his Controller father what he knows. Jake and the others overrule Cassie, deciding that Fenestre is the more pressing matter. Jake, without any prior intelligence or preparation, sends himself and the Animorphs to the billionaire's property. They are immediately attacked by gun-toting humans and pack hounds, and Rachel is shocked unconscious by a bug zapper. Ax is captured by the dogs. Jake and the others, shaken, need to find another way to break in. Jake travels to The Gardens zoo complex, and acquires a rhinoceros morph. He morphs and breaks through the entrance to the Fenestre mansion, impervious to human shotguns. The others follow, and morph their standard battle morphs.

They find Fenestre, along with Rachel and Ax in a suspended time state known as "biostasis". The Yeerk controlling Fenestre explains to Jake, Cassie, Marco and Tobias that he is Visser Three's twin brother - Esplin 9466 Lesser. Visser Three, unwilling to share his power with his sibling, banished him to Earth as a lowly telephone operator. Esplin, combining his Yeerk technical knowledge with his host's human knowledge, created a web service that would serve as a vast pool of information for the Yeerk invasion. The Visser was enraged, and has been plotting to kill him.

Jake asks Esplin how he survived without a Yeerk pool. Esplin unemotionally explains that he finds human-Controllers on the Yeerk forum. Every three days he has them kidnapped, splits the hosts' heads open, and feeds on the Yeerk inside. Fenestre admits that he is a cannibal serial killer. A horrified Cassie tries to attack him, but Jake stops her. He'd rather allow Esplin to kill as many Yeerks as he could - even it means sacrificing the host. Cassie is enraged. Jake threatens Esplin, and they leave with Rachel and Ax.

The next day at school, Jake was still feeling bad, it was nice that his parents wouldn't understand the decisions he makes, from life-and-death decisions, to keep making decisions when he makes mistake, and making decisions no human could ever make correctly-like deciding what to do with Fenestre. He then looks for Cassie, but he doesn't see her and realizes that she wasn't in school and Jake knew exactly where she was. He makes his way to the school roof and flies off in his falcon morph. He waste time heading for Gump's house, which was stupid because Cassie would have wait until he was away from the house, so Jake searches around for the nearest elementary school and heads there. He spots some kids at recess, and sees a little boy on the far side of the playfield with a large canine, but Jake knew that was really Cassie in her wolf morph. The boy pets Cassie and walks back to his classmates, and Cassie jumps the fence and fades towards some nearby trees. Jake calls to her and lands. They demorph and he asks her if that was Gump, she says yes. She explains to Jake that she pretended to be a magic, talking wolf to Gump, and told him not to go onto the chat room again, and to not talk about Yeerks to his father, and not to trust his father. Cassie then cries over doing such a terrible thing, but Jake explains to her that it was the best she could and that its hard to fight evil without doing some along the way. She walks away and Jake doesn't stop her. A few days later, the news reported a fire at a mansion, which turns out, belong to Fenestre. He was safe and no one was hurt, but Jake remembered warning Fenestre that he would be safe, only if he stayed in his house. But now that was no longer possible for him. He also wonders how the mansion burned down, did it happen on its own? Or did someone else start the fire? Jake guesses he'll never know.

A week goes by before Jake goes to Cassie's house. He finds her in the barn caring for some of the animals. Neither one asks the other questions and Jake helps her out. After a while, they start talking, and the others come over they talk about flying. But instead, they stay in the barn and help out with shoveling manure. They were them again.. for now.


Featured Characters:

Supporting Characters:



Morpher Morphs acquired Morphs used
Jake Rhino Fly, Siberian Tiger, Peregrine Falcon, Rhino
Rachel -- Fly, Grizzly Bear, Bald Eagle
Cassie -- Fly, Skunk, Osprey, Wolf
Marco -- Fly, Osprey, Silverback Gorilla
Tobias Fly Human, Fly
Ax -- Human, Fly, Northern Harrier


  • Animorphs warning book 16 flipbook

    Jake morphing Rhino flipbook, from the pages of the book.

    The cover quote is, "Now it'll take more than the truth to set you free...."
  • The inside cover quote is, "Sometime you have to blow your horn...."
  • When Ax is asked to identify the green aliens that are often described in alien conspiracies and abductions, he refers to the Skrit Na, and an adventure that Elfangor once had with them. The adventure that he's talking about is actually a part of Elfangor's journey from The Andalite Chronicles where he finds Loren and Chapman held hostage aboard the Skrit Na's saucer-shaped ship.
  • ANIBASE : Cassie is the only dissenting voice amongst the Animorphs regarding the Internet in this book -- and it turns out that she feels the same way Katherine Applegate does! Here's what K.A. had to say about the Internet:

"I'm afraid I have a fairly one-sided view of the Internet. I realize I'm using it right now, but aside from this sort of experience, I find the Web a huge disappointment. If I want research, I can get what I need ten times faster in any Barnes & Noble. As for chat rooms, they tend to sink rather quickly to the level of the lowest common denominator, which, given the anonymity of the Web, is pretty low. Then again, maybe I'm just old."

  • Fans created web sites pretending to be real web sites based on the sites mentioned in this book, such as


International Covers

International Back Covers

Taken from

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

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