The cowboys were skeptical at first. But the aliens fixed the water reclamation. They taught the homesteaders how to grow frost-resistant corn using mycorrhizal fungi from another galaxy. In return, the humans gave them land, livestock, and the one thing no star chart could provide: a place that didn't want to kill them.

The film takes place in the 1880s, in a small town in Arizona. Doc Holliday (Bruce Sterlings), a doctor and gambler, helps an alien named Ooroon (played using CGI) who is on the run from an evil alien warlord, Rizzle. The alien's spaceship crashes on Earth, and Ooroon is forced to interact with the humans.

If you want the "updated" version of the story, the original graphic novel remains the definitive source of inspiration. Interestingly, the creator of the comic recently noted that he would love to see a new version that leans harder into the "tech" used by Native American tribes—such as anti-gravity horses—elements that were largely left out of the Favreau film.