Yul Brynner, condemned revolutionary, leads a band of escaped convicts and their hostages across the believably Arabian - but actually Mojave - desert, encountering film-stealing James Mason on the way. No more plot than that, but they do enough for it not to fizzle out. It's not bad at all - solid, not gung-ho, and plenty of truck-driving action.
It certainly jumps straight into a decent jeep/truck chase, and if you enjoy watching a bright yellow truck being mightily abused, and cringeing when it doesn't topple over, you'll love Escape From Zahrain. At the end, the appearance of a P-51 strafing our plucky travellers is also an exciting bit of cinema. In the middle, there's solid character conflict, Yul demonstrating why he's the boss.
The sound stage sequences definitely look as though they were filmed on the (cheap) Star Trek lot, but the actual desert sequences are really good, as far as trucks being driven across the desert goes. Yul Brynner appropriately regal (permo-turban), Sal Mineo reprising 'Rebel Without A Cause', Jack Warden doing 'Trusty American Slob', and Madlyn Rhue making up the numbers as a nurse. Anthony Caruso as an unstable psychopath provides a bit of light relief.