Malle himself has said about this film: "Opaque, sometimes clumsy, it is the most intimate of my films. I see it as a strange voyage to the limits of the medium, or maybe my own limits."
The world is embroiled in a war between men and women, and, to escape it, Lily (Cathryn Harrison) flees to a country estate on which a number of surreal and unusual events take place. Naked children round up pigs and sheep. On the estate are three adults: a man, Brother Lily (Joe Dallesandro), his sister, Sister Lily (Alexandra Stewart), and The Old Lady (Therese Giehse). Brother Lily tends to the upkeep of the grounds and does not speak but somehow communicates through touch. Sister Lily (Alexandra Stewart) helps on the estate with the rounding up of sheep and feeding the children. The Old Lady is a demanding bedridden woman who communicates with a large rat, and operates a ham radio next to her bed. When she is hungry, she seeks milk and is breastfed by Sister Lily, and later by Lily.
Brother Lily kills a hawk with a sword after it flies into the house. This angers Sister Lily, and they fight.
Lily pursues a unicorn around the estate. It later turns up in the Old Lady's room, and Lily prepares to breastfeed it.Cathryn Harrison as Lily
Therese Giehse as The Old Lady
Alexandra Stewart as Sister Lily
Joe Dallesandro as Brother Lily
The film was shot in Malle's own 200-year-old manor house and its surrounding 225-acre (0.91 km2) estate in the lush, wild Dordogne valley in Quercy, near Cahors, called "Le Coual," or "The Crow's Call." The house and grounds were actually the beginning inspiration for the film, according to Malle in an interview in Cinefantastiqu: "It began with the fact that I wanted to shoot the film in my own house. Black Moon certainly comes very much from the place where I live, the kind of countryside around the house. There's something very ancient, maybe archaic, about it, also something...hostile." Malle also said that the film was influenced by his admiration for Lewis Carroll's Alice in Wonderland.
Malle hired Sven Nykvist, Ingmar Bergman's cinematographer, to shoot the film, and wanted there to be no scenes in which there was direct sunlight. They shot indoor scenes on sunny days until the light was right for the exterior shots.
Knowing that the film would be difficult for audiences as a full-length feature film, Malle considered releasing it in a much shorter version, and actually prepared a one-hour cut, removing scenes that he felt did not work.
At the time of its release, Black Moon received mixed reviews and vanished into obscurity. It has since been screened at theatrical revivals and aired on the television channel Turner Classic Movies. On the review aggregator website Rotten Tomatoes, the film holds a 50% positive rating based on ten reviews with an overall rating of 5.4/10.
Vincent Canby of The New York Times thought positively of the film, calling it "baffling and beautiful and occasionally very funny." He also said, "Black Moon is a poetic vision made to look so absolutely literal one doesn't question the validity of the images." Conversely, Roger Ebert thought negatively of the film as he recalled in a later article of his: "[Louis Malle] just made a movie that was an extended, surrealistic daydream. Perhaps it would have been safer if he hadn't."
Film critic Jeff Stafford wrote about it:
Walking a fine line between fantasy and reality with the two occasionally merging, Black Moon refuses to conform to a conventional storyline and a description of the fantastical events that take place could easily give one the wrong impression and misrepresent the cinematic experience Malle intended. The director was well aware of this, saying "I don't know how to describe Black Moon because it's a strange melange - if you want, it's a mythological fairy-tale taking place in the near future. There are several themes; one is the ultimate civil war...the war between men and women. I say the 'ultimate civil war,' because through the 1970s we'd been watching all this fighting between people of different religions and races and political beliefs. And this was, of course, the climax and great moment of women's liberation. So, we follow a young girl, in this civil war; she's trying to escape, and in the middle of the wood she finds a house which seems to be abandoned. When she enters the house, she obviously enters another world; she's in the presence of an old lady in bed, who speaks a strange language and converses with a huge rat on her bedside table. She goes from discovery to discovery - it's a sort of initiation." The film has obvious connections to the writings of Lewis Carroll as well as other films from the same period such as Robert Altman's Images (1972), which shares a similar fascination with unicorns, and Ingmar Bergman's bleak war allegory, Shame (1968). Malle freely admitted that Black Moon "conveys my admiration for and curiosity about Alice in Wonderland. And in the part I deliberately cast this English girl, Cathryn Harrison..."
Pauline Kael said about Black Moon:
Louis Malle is temperamentally unsuited to the meandering, enigmatic, post-apocalypse fantasy he attempts here; he's a sane man trying to make a crazy man's film...There's no obsessive quality in the disordered vision, and no wit. It's deadly.
Jean Roy of Cinema said
[W]hat is really inadmissible here is that Malle has everything: 20 years of experience behind the camera; Therese Giehse, the creation of [Bertolt] Brecht; Joe Dallesandro of Andy Warhol's Dracula , in which he showed us the acting potential he had hidden; Sven Nykvist, [Ingmar] Bergman's cinematographer for 30 years. And with all this, the film accomplishes nothing.
Other critics differed. Susan Sontag said it was "mesmerizing", and Kevin Thomas of the Los Angeles Times called it "intensely personal and so very beautiful".
Black Moon was the winner of two French César Awards for Best Sound and Best Cinematography.
A digitally restored version of the film was released by The Criterion Collection in June 2011.