Klute (1971)

Directed by Alan J. Pakula, this movie has a young Donald Sutherland as a detective from Palookaville, PA (actually, Tuscarora), who investigates a missing-persons case in the Big City. Jane Fonda is a jaded prostitute/model/actress with a connection to the missing man. Sutherland and Fonda slowly form a working relationship, as she takes him into the Underworld to follow various leads. He's a total straight man - literally jug-eared, and wearing dorky jackets, he is out of place in the wild partying seventies underground dives she brings him into, but has a masculine, old-school sense of purpose that somehow forces her to yield and help him with his investigatins, and eventually to sleep with him. For fun! Not for money!

There are a couple good what-is-the-sex-industry-all-about moments in here, like when Fonda meets with her psychiatrist and talks to her about her inability to get out of the trade (she likes the sense of control that she has over events, which the film opposes quite well to the moments when she gets passed over at modeling calls and auditions). But overall, it chafes that she's the ultimate woman-on-her-own who figures out that she can't really hack it without a man for protection. "Looking for Mr. Goodbar," from 1977, seems to be sort of a more violent spiritual sequel to this movie.