This is an experimental Catalan Spanish production. Because of the film's ostensible science-fiction theme, the filmmakers were able to produce a highly political adventure film; the film's political content was not tampered with by Franco's censors. However, the film had an unusually intense focus on sexual activity (for a Spanish film at that time), which was frowned on by the censors, and it was not approved for general release by the time it was shown at the Venice Film Festival in August, 1971. A drug has been discovered, Liberxina 90, which will erase "establishment" conditioning from the human mind. It has fallen into the hands of some diversely anarchistic revolutionaries who spend most of the film discussing how and whether to use it; should they wait for the forces of "history" to undermine society or speed things up using the drug? They are finally forced into action by the police who are, somewhat ineptly, hunting them down. Spanish filmmaker Carlos Durán made his feature-film debut in 1961 with La Plage/The Beach and went on to become a key figure in the "Barcelona School" of cinema. A native of Barcelona, Durán launched his professional career as an assistant director under such established filmmakers as Pierre Gaspard-Huit, Jaime Camino, and Vicente Arandfa following his graduation from France's prestigious Institut des Hautes Etudes Cinématographiques. Durán's first Spanish feature was Liberxina 90 (1970), a documentary biography of Valencian singer Raimon, who during the '60s was a popular figure among resistors of Franco's regime; it was censored and barred from release. Following Franco's death, Durán became the manager of Lolafilms and accepted a commission from the Catalan Government to make a series of institutional documentaries.