In San Francisco in 1920, Sam Spade (Humphrey Bogart) and Miles Archer (Jerome Cowan) was approached by Miss Wonderly (Mary Astor) to go follow a man, Floyd Thursby, who has apparently ran off with her sister. The two decided to do this case for her. Later that night, Sam was told that his partner was shot and killed while spying on Floyd. Sam gets questioned about the murder and