Prot is a patient at a mental hospital who claims to be from a far away Planet. His psychiatrist tries to help him, only to begin to doubt his own explanation.

a strange stranger in New York's Central Park station in front of witnesses , it comes from another planet : the K- PAX . Police after hearing the news that he was crazy , him on the train bound for a mental hospital , entrusted to a kindly psychiatrist Mark (Jeff Bridges ) . The patient claimed to Prot, ( Kevin Spacey ) , is optimistic and confident guy . Are forever talking about him in the hospital to patients and physicians about life on their own K - PAX planet 7000 light years away . His description is so realistic , nuanced , Mark confused and gave the other mental patients bring hope . Even more amazing is that some of the patient's condition actually has improved, the impact of the Prot and even marks the doctors themselves feel that through contact with Prot , overcome self-doubt, and learned the inner feelings to the loved ones reveal ...
Prot announced that he would leave the Earth at the end of the summer to return to the planet of K - PAX . She has competing and went with him . Scheduled to leave the day is getting closer , more and more excited patients will soon have the opportunity to extraterrestrial marks the doctor fell into a trap , whether Prot is a mental patient ? Believe the scientific diagnosis, or believe Prot confident statement ? Marks and even the ability to distinguish between reality and fantasy doubt ...