Johnny Moon (William Shatner) is half-Comanche, half white and forever getting mixed up with his twin brother Notah. This would not be so much of a problem if Notah were a law abiding citizen, but Johnny has embraced the white side of his heritage while his twin has opted to stay with the Comanche tribe, and he wishes to stir up trouble almost daily. When Johnny is almost lynched by a mob wanting to get their revenge for another murder Notah has committed, he does manage to escape but for him, this is the final straw - now he tracks down his sibling and gives him an ultimatum. One of them must die...
In between seasons of Star Trek, William Shatner found himself with a bit of free time to travel to Spain to shoot this tiny budget Western. It might have been seen as an opportunity by the star to make his name internationally the way that many of his fellow actors had done, but as it turned out he was wise to return to the States and resume the role of Captain Kirk, because it's safe to say nobody will best remember him from White Comanche. Those expecting a Shatner scenery-chewing fest will be let down as while he does go over the top as the Indian, most of the plot concentrates on the considerably more restrained Johnny.
To the point that you begin to wish we could spend more time with the bad boy rather than the good, because Johnny isn't exactly a laugh riot. Notah, on the other hand, lives a far more exciting lifestyle, as we see near the beginning where he holds up a stagecoach (Shatner does his own "jump onto the horses" stunt here, presumably not due to bravery but more down to the lack of stuntmen hired), shoots various of its passengers, and rapes showgirl Kelly (Rosanna Yanni, from a few Jacinto Molina movies) who was travelling on it. All while tripping on peyote. Kelly resolves to avenge her violation, and takes aim at Johnny, not realising, like so many others, that he and his brother are two separate people.
The old good twin/evil twin plot has served filmmakers well, but here we don't see enough of both of them to work up a decent amount of tension. The story gets sidetracked to increase the running time with a man Johnny saves from another lynching wishing to repay him, then the would-be lynchers shooting up the town to get their own back, fair enough for a Western, but it seems like it's been parachuted in from another movie. This is a pity, as evil doubles have been a staple of sci-fi television for decades, and Shatner himself portrayed one in one of the most hilariously entertaining Star Trek episodes, so you might be anticipating amusement reaching those giddy heights.
That's where you would be mistaken, as the brothers don't even get a brawl to indulge in, and we return time and again to Johnny mumbling to those accosting him or holding him at gunpoint that they have the wrong man, yet never explaining why as he mysteriously keeps Notah's existence a secret, possibly thanks to his desire to kill him alone. He does let on to Kelly when she gets him alone in his hotel room, and she notes the difference between them: one has blue eyes, the other black. Everything else it appears they share, including the same pair of blue trousers, although not the shirt as Notah spends his time stripped to the waist as Shatner struts around peacock fashion. Also worthy of note is Joseph Cotten, there one assumes for the same "sure, just pay me" reasons as The Shat, playing the Sheriff with little impact. Fans of the leading man will be keen to see White Comanche for completeness' sake, but it's really pretty dull. Music by Jean Ledrut.