"K-PAX" is a science fiction novel written by Gene Brewer, published in 1995. The story follows a man named Prot, who claims to be an alien from the planet K-PAX. He arrives at a mental institution, where he captivates both staff and patients with his extraordinary knowledge and unique perspective on life. The novel explores themes of mental health, reality, and the nature of existence. As Prot interacts with the psychiatrist, Dr. Mark Powell, the boundaries between sanity and insanity blur, prompting questions about what it means to be human and the possibility of life beyond Earth.