You don’t—can’t, actually—watch Alejandro Jodorowsky’s post-drug culture art films in the same way that you watch most other films. The Jodorowsky experience has more in common with the 16th century art experience. You don’t follow a plot; you observe themes via onion layers of iconography and symbolism. The story here is simple: A lowly, loincloth-clad thief in a state of spiritual crisis works with a master alchemist in order to achieve capital “E” Enlightenment via scaling a holy mountain where the secrets of immortality are found. To tell it, madman artist Jodorowsky crams multiple messages into nearly every shot, as in a painting (there’s remarkably little dialogue). He draws imagery from Christianity, Buddhism, Tarot, Freemasonry, ancient mysticism and magic, astrology, art, and history. And to Jodorowsky’s credit, even if you don’t always GET his allusions, the imagery always startles and engrosses. 
The first two-thirds are where the really complicated sequences happen. It’s where our thief, equated with both Christ and The Fool tarot card, gropes at initial enlightenment, finds the master (played by the mustachioed Jodorowsky himself) and meets his companions, each of whom represents a planet’s astrological traits. The film introduces the companions via narrated dramatizations of their stories, packed full of surreal jokes and commentary on politics, sexuality, and the big, bad “material world”. It’s some of most entertaining stuff in the movie. We get memorable imagery like a sex scene where semen takes the form of little pearly hearts, a giant robot vagina that becomes aroused when penetrated and gives birth to a baby machine, and totalitarian police gunning down radical students whose blood and entrails pour out in the form of fruit, foliage, and live birds.
Jodorowsky made this after the success of El Topo, with financing partly from John Lennon and Yoko Ono. Filming took place in Mexico, where Jodorowsky was a controversial figure, receiving death threats and ominous phone calls from government officials during the shoot. The actors are also put through trials. Nearly every featured character strips naked and shaves his or her head (at one point George Harrison was interested in playing the part of the thief, but balked at a scene in the script where the character is bathed nude and his anus is washed in close-up; Jodorowsky ended up going with an unknown actor, Hector Salinas, and kept his precious anus-washing shot). For one scene, not used in the movie, Jodorowsky claims to have given all of the actors psychedelic mushrooms.