This film is definitely a case of excessive self-indulgence. The initial scenes are genuinely unsettling; a woman finds herself attacked in an office setting by coworkers who restrain her on what appears to be an altar. However, the explanation turns out to be far less sinister – just a group of restless students amusing themselves with their own twisted game. They then meet "Duchemin" (played by Pierre Zimmer), who entertains them with tales from his time in North Africa and introduces the idea of a transformative powder. Naively believing him, they travel to stunningly beautiful homes along the Tunisian coast where the remainder of the story unfolds. “Surreal” doesn’t even begin to describe it; forget about a conventional narrative as the group begins experiencing hallucinations and engaging in disturbing scenarios reminiscent of the Marquis de Sade. It might be intended as erotic, but the nudity—primarily female—doesn't necessarily feel alluring or stimulating. At times, particularly during the latter portion, it feels like watching an old "Playboy" photoshoot. There are moments when the film’s randomness and lack of predictability prove effective, keeping you engaged for a while, but as it approaches what could be considered an ending, I found myself wishing I had encountered one of those venomous scorpions that seemed to appear earlier on. The movie drags considerably, feels overly long, and there's no effort made to develop the personalities of these attractive, introspective young people who are easily manipulated by their new guide. It was presented at the defunct 1970 Berlinale, and while I am glad I saw it, I have absolutely no desire to view it again.

Source on TMDB