Archie Bollen (Scott) is a middle-aged San Francisco physician in the midst of a divorce. After meeting Archie at a gala event, sexy, troubled socialite Petulia (Christie) pursues him avidly, hoping to embark on a torrid affair, even though she is married to David (Chamberlain), a handsome swinger with an abusive streak. But Petulia has another connection to Archie too, a secret bond she never divulges, even as their lives become increasingly tangled.

Set in San Francisco at the height of the Summer of Love, Richard Lester's stylish, offbeat melodrama pays homage to the swinging sixties in more ways than one. Through jarring jump cuts, flashbacks and "flash forwards," and glimpses of the Grateful Dead performing for a crowd of gyrating hipsters, the director evokes the psychedelic ethos of the era as a way in to the turbulent lives of Archie and Petulia, each of whom is suffering a private torment: she is a victim of abuse, while he just wants to "feel something." Scott and Christie are exemplary in their roles, while Chamberlain gets to look pretty, sulk, and act like a cad. Shot by Nicholas Roeg, "Petulia" is a trippy tale of love and confusion that explores the humid underside of flower power.