Kevin Spacey plays Prot, who is committed to a mental hospital when he says that he is from another planet called K-Pax and that he traveled to Earth on a beam of light. He begins treatment with Dr. Mark Powell (Jeff Bridges). Prot's story is so complete -- and so enticing -- that Powell is determined to find out the truth, more for his own sake than for any therapeutic benefit to Prot. Others are enthralled by Prot's stories. Mark's astronomer brother-in-law, despite his commitment as a scientist to rational empiricism, is so intrigued by Prot's answers to his questions that all he can say is, "I don't know what I believe. I only know what I saw." Prot's fellow patients begin to clamor to go back to K-Pax with him.

K-PAX has a couple of daunting movie cliché obstacles to overcome: the only-in-movies "land of cute crazy people" setting and the always popular "patient heals the doctor" theme. Despite all of that and an unwise decision to tie things up too neatly at the end, the film manages to make it work, thanks to outstanding work by stars Kevin Spacey and Jeff Bridges and a script that is warm, witty, and genuine.

Director Softley has a delicate touch. Sunlight splintered by a prism, a child's ruby slippers, Spacey is outstanding, as always, resisting the temptation to make Prot too adorable. The subtlety and grace of his performance are astonishing. Bridges does a fine job as the doctor, and his scenes with Spacey make the movie.