In the near future Earth is at war with the inhabitants of Alpha Centauri, who want to destroy mankind and take over the planet. Many of Earth's cities are enclosed in protected domes. Spencer Olham, one of the scientist working on a new weapon, is suspected of being an impostor, a biological weapon created by the aliens. The authorities capture him and are about to dissect him--but he escapes. The rest of the movie is about him uncovering the truth, to prove that he is indeed the original human. Sort of like a future version of THE FUGITIVE. This is also one of those movies where you keep and going back and forth on who is the impostor and who isn't--and the ending comes as a surprise. Gary Sinise (THE STAND) is great as Olham and Vincent D'Onofrio is effectively chilly as the government agent intent on hunting him down. Like Speilberg's MINORITY REPORT, this screenplay is based on a short story by Philip K. Dick. Between the two I'd say IMPOSTOR is the more enjoyable movie.