Her name is Roxy, but the village girls call her Toxic. With peroxide-blond hair and the Lolita-like naiveté of a vintage sexploitation-movie heroine, Roxy wanders through a post-apocalyptic world as unfamiliar to us as it is to her — for we have all stepped into the parallel dimension that is underground filmmaker Bertrand Mandico’s erotic imagination. Welcome to the dirty paradise of “After Blue.”

Humans have poisoned earth and fled to a new planet, which they’ve dubbed After Blue (a slightly awkward use of English in this otherwise-French-language production, no doubt intended to sound chic to Gallic audiences). Screens and machines have since been banished, making way for a kind of old-world mysticism of sparkling dust, psychedelic lights and occult symbols — like a third eye, superimposed over the pubic triangle of the most enlightened. Operating in the mode of Polish porno-surrealist Walerian Borowczyk, Mandico creates sensual mood trips using only practical effects (this one could be the “Barbarella”-style sci-fi film-within-a-film being produced in Mandico’s 2018 meta-textual short “Ultra Pulpe”).

Though its weak bounty-hunter plot makes almost no sense, “After Blue” satisfies that thirsty spot in our psyche too few films succeed in tickling, where dreams are born, hormones churn and logic simply doesn’t apply. The actors are stiff and the dialogue silly, but it’s intuitive enough. Mandico sets the stage via a chorus of overlapping narrators, their disembodied heads (and naked hirsute shoulders) floating in space: The atmosphere on After Blue is toxic to men, whose hair grew inwards and killed them off. Only women remain, adapting to this new matriarchal world of self-heating sex robots and artificial insemination.

The few survivors form small clans, doing their best to maintain some kind of social order, wherein law-breakers are hunted down and killed before such evil can spread and ruin another planet. Roxy (Paula Luna) is too inexperienced to understand such things, alas, though the same goes for audiences, who drift along on a series of woozy set-pieces, trying to make sense of the movie’s out-there visuals. Picture a mashup between Raquel Welch wet dream “One Million Years B.C.” and kitsch space opera “Flash Gordon,” executed by an art school prodigy on an acid trip. It’s not something one watches sober, but rather projected on the wall of an avant-garde gay bar.

Early on, Roxy encounters an outlaw who calls herself Kate Bush (Agata Buzek) buried up to her neck in sand. Not knowing better, she frees this stranger, and the two women share an intense, homoerotic moment on the beach. Kate Bush then escapes, but not before zapping Roxy’s friends with her rifle — all the weapons on After Blue have designer names, though that detail is better discovered in context — which creates problems for Roxy and her overprotective mother Zora (Elina Löwensohn) back home.

Roxy and Zora are banished together, ordered to hunt down Kate Bush. But the longer Roxy spends exploring the world beyond her tribe’s claustrophobic cave, the harder it will be for her to return to the sheltered existence she knew before. This archetypal quest doesn’t amount to much, but it’s more than enough for Mandico to work his magic. His imagery can be mesmerizing, from absinthe-hued dinner parties where the host spits “cosmic urine” to the smoldering landscapes from which giant seedpods and jagged crystals erupt.

“After Blue” is only the director’s second feature, following 2017’s “The Wild Boys” (a queer twist on “the Lord of the Flies” full of borderline-pedophilic imagery). Story is not his strong point, but the experience of more than a dozen shorts made over nearly two decades has given Mandico the chance to hone his style, arriving at a playful form of pastiche. Track down his half-hour “Our Lady of Hormones,” if you can. It’s the project that best demonstrates Mandico’s unique mix of absurdist humor and psychosexual tension: a campy ménage-à-trois comedy in which two lesbians adopt a curiously endowed alien organism that looks like something David Cronenberg or David Lynch might have ordered, and which both want all to themselves.

Though “After Blue” has spent nearly a year on the festival circuit, the film made its world premiere at Locarno a month before “Dune,” and in a way, Mandico’s transgressive fantasia provides the ultimate art-house counterprogramming option: Instead of testosterone-driven star wars over sandworm-infested spice fields, we find Toxic femininity trying to find her place on a planet full of screaming caterpillars and madness-inducing mountain powder. Those parallels can hardly be accidental, though Mandico’s allusions to other artists and influences are so myriad, it doesn’t feel as if he’s attacking “Dune” directly. In a way, he’s queering the entire canon of masculine-made sci-fi, offering a more sensual, Sapphic alternative. For those brainwashed into thinking the genre can only be one thing, the experience just might open your third eye to other ideas.