John Müller, who recently got out of jail, plans a heist at Rocky Stansyck's illicit casino. After the heist goes awry, the mobsters kidnap a few of Müller's guys and make them identify the others before murdering them. Müller chooses to flee the town and go into hiding because Stansyck has a reputation for finding and eliminating his adversaries, no matter how long it takes. Frederick, his law-abiding brother, suggests that he take an office job, but he soon determines that working for a living is not for him. A fortuitous meeting with Dr. Swangron, a dentist, shows that Müller resembles Dr. Bartok, a psychologist who works in the same building, with the exception of a big scar on the left side of the doctor's face. He takes advantage of the situation and starts investigating Bartok, even sneaking into his office to look through his documents. Evelyn Hahn, the doctor's secretary, finds him. She kisses him, thinking he is her boss, but she soon discovers he is not him. Even though she has grown resentful and says she has given up on ever falling in love, he convinces her to go out with him. With the help of the fact that Bartok studied psychoanalysis in medical school before leaving, Müller sets out to mimic him. He cuts the same scar on the right side of his own face using a picture of the doctor as a guide. It is not until he has already killed Bartok and is getting ready to throw the body into the river that he realizes that Bartok's scar is on the left side of his face, and that Muller's scar is on the wrong side because the negative must have been accidentally inverted when the photo was printed. He follows through on the plan nevertheless, and nobody sees the difference—not even Evelyn or Bartok's patients—apart from the office cleaning lady, whose suspicions he manages to allay. Müller then learns that "he" has a girlfriend named Virginia Taylor and that they frequently visit the upscale casino Maxwell's. Additionally, Bartok has been losing a lot. The trail leads to Bartok when a distressed Frederick Müller attempts to get in touch with his brother. Frederick is persuaded by the scar that the man he sees is just a lookalike. Evelyn, who was not aware of the transfer at first but is now quite suspicious, discloses that John Müller claimed to be traveling to Paris. Frederick Müller informs "Bartok" that Stansyck has been found guilty of "income tax difficulties" and is about to be deported, so his brother no longer needs to hide. Later, Evelyn discovers that Müller must have killed the psychoanalyst and that he is a fraud. She buys a ticket to sail to Honolulu instead of turning him in to the authorities, even though he confesses to her. When Müller learns, he says he will accompany her, but she does not think he would pass up such a chance to make money. After making arrangements for additional medical professionals to care for his patients, Müller leaves for the dock. However, two individuals who wish to talk about Bartok's $90,000 gambling debt interrupt him there. They shoot Müller dead when he tries to escape. Unaware that Müller meant to fulfill his pledge to her, Evelyn sets sail.