Applegate Katherine Alice. The Animorphs 08. The Alien

After destroying the Kandrona, the Animorphs assumed that they would see people freeing themselves of the Yeerks. They are disappointed until the day they take Ax to the cinema. A man's Yeerk is seen dying publicly. However, a Controller-policeman kills the free man.
The Animorphs take Ax to the school as Philip, Jake's cousin, and a Yeerk who controlled one of Jake's teachers is seen dying as well. Chapman appears, orders the students to leave, and kills the non-Controller teacher.Jake and the other Animorphs become very angry with Ax because they feel betrayed. Innocent people are dying as a result of their actions. Ax retorts that they would not have destroyed the Kandrona had they known the consequences, to which Jake replies that he, Ax, still has a lot to learn about humans.
The next day, he meets with Marco to go to a bookshop in hopes that Ax would trust them if they trusted him. However, Marco forgets the money they collected for him to buy a book at home, so he and Ax go to Marco's house to pick it up.
While Ax waits for Marco in the living room, he plays what he thinks is a game on Marco's father's computer called "Fix the mistakes". He ends up messing up the computer.It turns out that he had developed a new system that was very advanced. Before destroying it, he used it to communicate with his home world. There, an Andalite made him assume all the responsibility for Elfangor's action and is consequently forgiven. When he was about to speak with his parents, he is interrupted by a Controller whose loved one had died when Visser Three chose to sacrifice her after the Kandrona's destruction. To avenge her, he tells Ax where and when Visser Three feeds his Andalite body.Animorphs is an English language science fiction series of young adult books written by K. A. Applegate and published by Scholastic. It is told in first person, with all 6 main characters taking turns narrating the books through their own perspectives. Horror, war, dehumanization, sanity, morality, innocence, leadership, freedom, and growing up are the core motifs of the series.The story revolves around five humans, Jake, Marco, Cassie, Rachel, and Tobias, and one alien, Aximili-Esgarrouth-Isthill (nicknamed Ax), who obtain the ability to morph into any animal they touch. Naming themselves "Animorphs" (a portmanteau of "animal morphers") they use their ability to battle a secret alien infiltration of Earth by a race called the Yeerks. The Yeerks are a parasitic race of aliens resembling large slugs that take humans as a host by entering and merging with their brain through the ear canal. The Animorphs fight as a guerilla force against the Yeerks, led by Visser Three, and their program to take over the human race. Morphing into animals allows them to battle the various armies of aliens that the Yeerks use, but it also protects their identities. As far as the Yeerks know, only Andalites like Ax have the ability to morph, and if they knew that the Animorphs were mostly human they would be able to easily find out who they are. Protecting their identities becomes more and more difficult as the series goes on because though someone with the ability to morph can change into any animal that they touch, they can only stay in a morph for two hours or they will permanently become that animal. Throughout the series, we see how the war affects the characters in different ways, mentally and physically.