Robert Altman’s 1977 psychodrama 3 Women is set around the pool of an apartment block and inspired by the director’s dreams. Fortunately that’s where the similarities to M. Night Shyamalan’s Lady in the Water end.

Also inspired by Ingmar Bergman‘s Persona, Altman claims this movie came to him in a dream fully formed and even cast, in which case kudos to his subconscious because Sissy Spacek as the shy Pinky and Shelly Duvall as the perky Millie make the perfect match for this unique film. They’re literally Pinky and Perky.

Duvall apparently developed much of the character of Millie herself, a lonely (everyone in Altman movies is lonely) consumerist who’s constantly getting her “English mustard” dress caught in the door of her “French mustard” car. She also has a streak of exaggerated maternalism (she obsessively organises recipes by how long they take to cook) that draws her towards the childlike Pinky, timid and mercurial like Spacek’s Carrie the previous year.

The pair meet working at a health spa for the elderly (there’s a pool at every setting), where Pinky becomes infatuated with Millie for her oblivious levels of confidence. Millie talks constantly despite always being ignored, as though in her own world, which Pinky also seems to occupy.

This sense of shared delusion is enriched by dreamy imagery and strange symbolism: reflections, twins, echoed dialogue and an atonal score by Gerald Busby. Water floods the screen suggesting amniotic fluid, its tide mark rippling like an umbilical cord over bestial images painted across the swimming pool by the pregnant Willie (Janice Rule), the titular third woman.

Fluid, overlapping identities emerge from Altman’s vision, almost like a female version of Fight Club. Even as Pinky starts to read Millie’s diary and wear her clothes, the film never conforms to the usual Single White Female bunny boilerplate, remaining as unpredictable and inscrutable as a dream (and an Altman flick) until its dark final moments. And no one does scared like Shelly Duvall.

Altman’s cynicism towards Hollywood is also present, reflected in Willie’s unpleasant husband (Robert Fortier), a former stuntman who owns a disused ranch covered in fake rocks like a set from an old Western. Artifice and isolation run deep through the picture’s dusty dreamscape, its abandoned locations and tinned food (spray cheese anyone?).

3 Women is a fascinating and elusive story about female, familial relationships and all the things women are supposed to be.