According to Prot, K-PAX is a planet far beyond the reach of humans, light years away. Prot also states that he is not human and is visiting Earth from K-PAX. Prot quickly finds himself in a mental hospital, and under the care of DR. Mark Powell. Dr. Powell does his best to diagnose and treat Prot however he soon asks himself whether or not Prot could be an extraterrestrial. The movie never answers this question, but after viewing some of the occurrences in the film, it is obvious that Prot is an alien.
Evidence supporting Prot's claims of being an alien can be witnessed throughout the movie. Nearly every time Prot opens his mouth in the movie, he spews out knowledge and facts that no earth born man could have known at the time. This example is amplified by the schooling Prot gives a group of astronomers at a planetarium. Prot showed them where K-PAX was and how it orbited between its two suns. None of the astronomers could refute anything Prot said. However astronomy isn't Prot's only area of scientific expertise, he knows a thing or two about physics as well. He displays an uncanny understanding of Einstein's theory, and while in the planetarium, gave the astronomers a demonstration of faster than light travel.
Another thing about Prot that leads the viewer to believe he is an alien is his ability to see ultra-violet light. Throughout the movie, unless he is in the dark, Prot has on sunglasses to protect his eyes from the intense light of Earth's sun. Also, early on in the movie, there was a scene where Prot and Dr. Powell were facing each other on opposite sides of two-way glass. The remarkable thing about this scene was that Prot was able to follow the doctors every move through the two-way glass. Another interesting.
physical attribute Prot has is his immunity to the various drugs the doctors at the hospital administer to him. Just being immune to certain drugs doesn't make you an alien, though if you combine that with his other attributes, it can certainly lead one to believe that something out of this world might be up.
