A sign in front of Nick's Pacific Street saloon, restaurant and entertainment palace in San Francisco invites customers to come in and be themselves. Among the motley group that frequents Nick's saloon are: Joe, a wealthy man who helps lonely drifters who take refuge in the saloon; Joe's faithful friend Tom, who three years before Joe had nursed back to health, and who now runs errands for him; and Willie, who endlessly plays a marbles pinball machine. One day at Nick's, a woman who calls herself Kitty Duval wanders in and is befriended by Joe. She tells Joe that her real name is Katerina Koronovski, but became Kitty Duval when she toured the country as a burlesque singer and dancer. Joe asks Tom to dance with Kitty, and they fall in love. Meanwhile, Dudley Raoul Bostwick, a lovesick young man desperately trying to reach his girl friend, Elsie Mandelspiegel, on the telephone, dials the wrong number, and ends up telling a strange, lonely woman that he is going to kill himself if she does not marry him. The woman, Lorene Smith, eagerly arrives at Nick's, but when Dudley sees that she is a homely, middle-aged spinster, he pretends to be somebody else. Kitty and Tom go out, and while they are away, an informer named Freddy Blick questions Nick about a blonde named Kitty Duval who has a police record in Chicago. Next, Joe tells a beautiful stranger with the initials "M. L." that he was once in love with a woman named Mary, whom he met in Mexico City, but who was engaged to another man. For a moment, the woman imagines that she is Joe's Mary, and he admits that he is still in love with Mary before she says goodbye. Later, Tom returns, and after he tells Joe that he wants to marry Kitty, Joe sends him out to buy a gun. Kit Carson, an old cowboy, then enters and tells Joe fantastic tales of adventure from his youth and comments that Joe is the first person ever to believe them. Elsie finally arrives and agrees to marry Dudley, and they leave together. After Willie finally wins his perpetual game of marbles, he leaves the bar. When Tom returns with a gun, Joe sends him on a job interview as a truck driver. Kitty then comes back and confesses to Joe that she was never in burlesque, but was involved in "other" things that make her unworthy of Tom. While Joe is away collecting poetry to cheer up Kitty, Blick returns and accuses her of being Katerina Koronovski, an ex-convict who spent two years in prison. Kit comes to Kitty's defense, but Blick beats him up and throws him out of the saloon. Blick then forces Kitty to prove she was a burlesque dancer by insisting she perform her routine on the stage. After Blick orders her to take off her clothes, she admits who she really is, defiantly asking Blick if he has the courage to admit the same. After Joe returns, a fight starts in which Joe tries to shoot Blick with his defective gun, then knocks him out with his fists. Nick enters and throws Blick out, and Tom announces that he got the job and will marry Kitty. Nick then tears up his sign, saying "Enough is enough."