Beyond the Valley of the Dolls

Three young womenâKelly MacNamara (Dolly Read), Casey Anderson (Cynthia Myers), and Petronella "Pet" Danforth (Marcia McBroom)âperform in a rock band, The Kelly Affair, managed by Harris Allsworth (David Gurian), Kelly's boyfriend. The four travel to Los Angeles to find Kelly's estranged aunt, Susan Lake (Phyllis Davis), heiress to a family fortune.
Susan welcomes Kelly and her friends, even promising a third of her inheritance to her niece, but Susan's sleazy financial advisor Porter Hall (Duncan McLeod) discredits them as "hippies" in an attempt to embezzle her fortune himself. Undeterred, Susan introduces The Kelly Affair to a flamboyant, well-connected rock producer, Ronnie "Z-Man" Barzell (John LaZar), who coaxes them into an impromptu performance at one of his outrageous parties (after a set by real-life band Strawberry Alarm Clock). The band is so well-received that Z-Man becomes their Svengali-style manager, changing their name to The Carrie Nations and starting a long-simmering feud with Harris.
Kelly drifts away from Harris and takes up with Lance Rocke (Michael Blodgett), a high-priced gigolo who has designs on her inheritance. Harris at first fends off the sexually aggressive porn star Ashley St. Ives (Edy Williams), but after losing Kelly he allows Ashley to seduce him. Ashley soon tires of his conventional nature and inability to perform sexually due to increasing drug and alcohol intake. Harris descends further into heavy drug and alcohol use, leading to a fistfight with Lance and a drug-addled one-night stand with Casey which results in pregnancy. Kelly ends her affair with Lance after he severely beats Harris. Casey, distraught at getting pregnant and wary of men's foibles, has a lesbian affair with clothes designer Roxanne (Erica Gavin), who pressures her to have an abortion.
Petronella has a seemingly enchanted romance with law student Emerson Thorne (Harrison Page). After a meet-cute at Z-Man's party, they are shown running slow-motion through golden fields and frolicking in a haystack. Their fairy-tale romance frays when Pet sleeps with Randy Black (James Iglehart), a violent prize fighter who beats up Emerson and tries to run him down with a car.
Susan Lake is reunited with her former fiancÃ© Baxter Wolfe (Charles Napier).
The Carrie Nations release records and continue to perform successfully, despite constant touring and drug use. Upset at being pushed to the sidelines, Harris attempts suicide by leaping from the rafters of a sound stage during a television appearance by the band. Harris survives the fall but becomes paraplegic from his injuries.
Kelly devotes herself to caring for Harris. Emerson forgives Petronella for her infidelity. Casey and Roxanne have a steamy, intimate romance. But this idyllic existence ends when Z-Man invites Casey, Roxanne, and Lance to a psychedelic-fueled party at his house. After Z-Man tries to seduce Lance, who spurns him, he reveals that he has female breasts, meaning he has been a female in drag all this time.[N 1] Z-Man then goes on a murderous rampage: he beheads Lance with a sword, stabs his servant Otto (Henry Rowland) to death, and shoots Roxanne and Casey, killing them.
Responding to a desperate phone call Casey made shortly before her death, Kelly, Harris, Pet, and Emerson arrive at Z-Man's house and try to subdue him. Petronella is wounded in the melee, which ends in Z-Man's death. Harris is able to move his feet, the start of his recovery from paralysis.
An epilogue follows, with a preachy, satirical voice-over monologue and scenes of Kelly and Harris (now in crutches) hiking on a log over a creek, and a final scene with the wedding of three couples in a courthouse - Kelly and Harris, Pet and Emerson, and Susan and Baxter - with Porter observing from outside the courthouse window.

Question: Where does Z-Man invite Casey, Roxanne and Lance to?
Answer: a party at his house