At a dinner celebrating twenty-five years of employment, cashier Christopher Cross is awarded an engraved watch by his boss, J. J. Hogarth, who later leaves the party with a stunning blonde, which impresses Chris. Walking home, Chris breaks up a violent quarrel between a man and a woman and, after the man flees, offers to escort the woman home. She introduces herself as Katherine "Kitty" March and asks Chris to buy her a drink first. Flattered and hoping to impress Kitty, Chris tells her that he is an artist and his modesty prompts her to suspect he is wealthy. The next day, Chris, who has been relegated by his shrewish wife Adele to practice his painting in the bathroom, grows depressed when she berates him for his lack of talent, and points out that her first husband died bravely as a detective. Frustrated, Chris sends Kitty a note asking to see her again. Kitty's idler boyfriend Johnny, the man who beat her, also believes Chris is rich and pressures Kitty to make a date with him. When they meet, Kitty claims she is an actress who finds it hard to make ends meet and asks Chris if she could pose for him, suggesting he rent a studio in which he could paint and she might live. When Chris admits he is married, Kitty feigns shock, but convinces him to rent the studio. Unsure how to provide the money for the studio, Chris considers stealing it from his employer, but asks Hogarth for a loan instead. Later at home, as Adele's nagging continues, Chris steals some of the security bonds left by her deceased first husband. Johnny helps Kitty select a lavish studio and demands she ask Chris for $1,000 more. When Chris unexpectedly visits the studio and finds Johnny with Kitty, she introduces him as a friend's boyfriend, but Chris's suspicions are aroused. Nevertheless, he brings several paintings to the studio and begins painting a portrait of Kitty. Later, Chris hesitates to provide Kitty with more money, but when she threatens to ask Johnny, Chris assures her he will get it for her and in desperation, begins stealing at work. Johnny, certain Chris is a famous artist, takes some of his paintings to a street vendor, who assesses them as amateurish, but offers to try and sell them. The next day, the vendor brings art critic Arthur Janeway to see Johnny, who tells him that Kitty did the paintings. Janeway declares the works highly original and when Kitty repeats some of Chris's phrases about art, the critic is impressed enough to offer to place the paintings with a prominent art dealer. Although Kitty is nervous, Johnny readily agrees. Sometime later, Adele spots the paintings with Kitty's signature in a dealer's window and accuses Chris of copying Kitty's work. Chris confronts Kitty about the paintings and she tearfully admits she had to sell them for money. Chris is pleased the paintings are selling and relieved to continue working in anonymity. At his office, a detective visits Chris, who fears his theft has been discovered, but the detective confesses to being Adele's first husband, Higgins. Higgins explains that he faked his own death and, now destitute, needs money to remain hidden. Chris, however, wants to pay Higgins to make a public return so he will be free of Adele. When Higgins hesitates, Chris tells him that Adele has the insurance money from his "death," which rightfully belongs to him. Chris arranges for Higgins to break in to the house that night to steal the insurance money, but traps him with Adele. Later, Chris visits Kitty and is dismayed to find her with Johnny. Overhearing Kitty declare her love for Johnny, Chris leaves, dejected. Kitty is relieved, but Johnny resents having lost their meal ticket and storms out. Chris returns, and although bewildered by Kitty's behavior, proposes. Kitty ridicules Chris's pathetic declaration and admits she has always loved Johnny. Outraged, Chris stabs Kitty to death with an icepick and slips away as Johnny comes back to the studio. The next day at work, an audit of the books reveals Chris's embezzlement. Hogarth is reluctant to prosecute and is sympathetic when Chris admits a woman was involved, but fires him. Johnny is arrested and tried for Kitty's murder, then is executed, while Chris remains silent. Guilt-ridden over the deaths of Kitty and Johnny, Chris attempts to hang himself, but is saved by neighbors. The haunted Chris takes to wandering the streets, trying to convince the police of his guilt, while the art gallery sells the "self portrait" of Kitty for an enormous fee.