Spoilers ahoy, if you care.
Zachariah and his friend Matthew (played by a very young Don Johnson) decide to go off and be gunfighters. They meet up with an inept game, have a few heists, then Zach gets the big idea to meet up with Job Cain, the fastest gun in the west. For some reason never really explained, Zach gets cold feet and he and Matthew split up. He then meets up with a mystical old coot who takes him for a romp in the desert that somehow fills in all the blanks. Matthew guns down his boss Job then comes looking for Zach. He finds him, they don't have a shoot out but instead wrestle and then when Matthew realizes the ridiculousness of it all, they ride off into the sunset together. The end.
Zachariah is clearly a product of it's time, and by that I mean the post-Woodstock, post-Easy Rider era. The movie just reeks of the tail end of the hippie era. That in itself isn't necessarily bad, but the problem comes in when Zachariah tries to be both a deep, loner looking for the greater meaning of life movie and a comedy and a head trip movie and a western. It succeeds at none of these things.
Simply put, this movie is a mess.
Part of the problem is that it is trying to be all those things I mentioned above and succeeds at none. The comedy (written by the Firesign Theater, who I always find the definition of hit or miss) really isn't all that funny. The drama isn't that compelling. The mystical stuff is clearly in the who cares category. Very little of this movie makes sense, motivation for any of the characters is really hard to figure out.
It's clear that this movie was trying to be a hip drive-in flick, so the fact that I'm watching it 35+ years after the fact with no chemical enhancements seems to be the rest of the problem. I have to say though, I'd be curious to know what combination of drugs would make some of these sad sack jokes funny. This movie wasn't for me, so maybe I just don't get it.
However, there are two shining moments in this film and I'm using this review as an excuse to post them. First, you get a totally gratuitous (and nonsensical) opening sequence featuring the James Gang. (They return later in the movie as Job Cain's house band.)
Next, and this is truly the highlight of the film, Job Cain is played by none other than Elvin Jones! And Elvin is truly awesome in his role. This is the best scene in the whole movie, though the beginning is truncated a bit.
I mean, damn. He just shot a man and then he busts out a crazy Elvin Jones drum solo. It really doesn't get much cooler than that.
Well, I just saved you the trouble of seeking this one out as there's really nothing else redeeming about it. Unless you are a hippy western completest, stay far away. If you do get it, do yourself a favor and skip to Elvin's scenes and revel in his awesomeness.
(Here's an alternate viewpoint that goes way more in depth than I think this movie deserves. Two points he makes are especially interesting to me: one is the gay overtones between Zachariah and Matthew, which I noticed but thought it was just my imagination. The second is the film's relationship to Siddhartha, which I missed but find myself slapping my forehead about now.)