Joe Gillis, an unsuccessful screenplay writer, escapes the finance men who are trying to reclaim his car by driving into the garage of an old mansion on Sunset Boulevard. Assumed to be someone else, he is led by Max the butler to the mansion's owner, silent film star Norma Desmond. Wishing to make a comeback, she hires him to rewrite her "Salome" script, then falls in love with him. Joe moves into the mansion as a kept man. Secretly, Joe is collaborating with a pretty young screenplay editor, Betty Schaefer, on another idea. Though she is engaged to his best friend, Artie Green, an assistant director, Betty falls in love with Joe. When Betty finds out about Norma, she asks him to leave Norma for her, but Joe can't unsettle her life, too. He decides, instead, to leave Hollywood. As he is leaving, a crazed Norma tries to stop him.