Larry "Doc" Sportello is a rather eccentric and unpresentable private detective who lives and works in Los Angeles in late 60-ies. Despite the fact that it is quite a peculiar man and lover of smoke grass, he knows his business well. One Document comes his ex-girlfriend Shasta, which asks to help her in one confusing case. She tells the detective that is mistress of the millionaire Mickey Vulfmana, who has a wife, and that, in turn, has a lover. Together with his wife and her lover wants to send Mickey in a Madhouse.
A little time passes and Shasta, along with his Knight disappears. Dock takes up the investigation, but he soon realizes that it is actually not so explicitly, as it seems at first glance. Investigation reveals before Sportello most dirty deeds that occur in the city, ranging from drug trafficking and ending unfair to hand the police and FBI agents. Doc will do everything possible to get to the bottom and find the missing girlfriend.