In Los Angeles, California, petty thief Edward “Eddie” Dash makes a meager living posing as a jazz musician on the Hollywood Walk of Fame. One day, Eddie drives to the Los Angeles County Probation Department, where he negotiates the terms of his community service. He agrees to spend 100 hours helping a patient from the Rivington Clinic sanatorium re-acclimate to outside life. George, the patient in question, is a pathological liar. When Eddie arrives, he has second thoughts about helping George, but George is elated to meet Eddie. They leave the clinic, and Eddie takes George to the Hollywood Wax Museum. There, George is frightened by “Frankenstein” and runs out of the museum, where he collides with a stranger named Al. The man mistakes George for his gambling partner, Abe Fielding. In order to repay a gambling debt, Al invites “Abe” to dinner that night. George protests, but Eddie sees an opportunity to make money and convinces him to go to dinner as “Abe.” At the restaurant, Al asks “Abe” about his five-month disappearance, and George pretends to be “Abe” by fabricating stories about his and Eddie’s recent adventures. Eddie is bewildered but tries to play along. After dinner, a woman named Elaine Fielding, who claims to be the real “Abe’s” wife, arrives in a limousine and demands to know how he spent the past five months. As they are driven home, Elaine tells “Abe” that she has no intention of believing his lies. She accuses him of having an affair and hints that the woman’s jealous husband will seek revenge. George assumes that his doppelganger has already been discovered by the husband and murdered without anyone’s knowledge. He attempts to explain to Elaine that he is not Abe Fielding, but she walks around in her lingerie, and he becomes tongue-tied. The next day, Eddie drives through Beverly Hills, California, to the Fielding mansion, where George has adopted the persona of “Abe.” Hoping to convince Elaine that Eddie should stay with them, “Abe” claims that Eddie is a famous prizefighter, and she agrees. When the friends are alone, Eddie expresses admiration for the far-fetched stories, but George is sad about succumbing to his illness as a pathological liar. That evening, “Abe” catches Eddie pilfering valuables from the mansion, but Eddie declares he is taking the objects to be cleaned. Later, “Abe” attempts to seduce his “wife,” but their tryst is interrupted when a car pulls into the driveway. Eddie answers the door and Rupert Dibbs, the real Abe’s business manager, storms into the house. Rupert welcomes “Abe” home, flirts with Elaine, and insults Eddie, who secretly pockets a pile of cash and several credit cards before driving away. George, as “Abe,” feels bad about the ruse and tells Elaine that he must leave. He returns to his therapy group at the Rivington Clinic. Meanwhile, Elaine meets with Rupert, who reveals that she is an actress hired to impersonate “Mrs. Abe Fielding.” Elaine wants out of the scheme, but Rupert convinces her to give the “role” another try. Rupert then goes to the county jail to pick up Eddie, who had been arrested for stealing the real Abe’s credit cards. Rupert tells Eddie the truth about Abe Fielding. In real life, Abe was a free spirit who traveled the world, and none of his father’s business associates, including Rupert, knew much about him. When Abe’s father died, the young man was set to inherit a brewery fortune. After a brief search, it was discovered that young Abe Fielding had died in a “freak accident.” Rupert, coveting the inheritance for himself, needs to keep the estate out of probate, so he chose George to pass as “Abe,” thinking the impersonation would be easy for a pathological liar. With the exception of Eddie, the people George met after leaving the hospital were actors hired to corroborate “Abe’s” identity. Rupert offers Eddie $10,000 to bring George back from the Rivington Clinic and continue living “Abe’s” life. When “Abe” returns to the mansion, he attempts to impress Elaine, taking her to a German restaurant and delighting her with a yodeling song. They spend an intimate evening together. The next day, Elaine and Eddie take “Abe” to the dentist, per Rupert’s request. While sitting in the waiting room, they realize that Rupert wants the dental records so that he can kill George, pass him off as “Abe,” and claim the company fortune. Elaine and Eddie confront Rupert at his office, but the businessman denies their accusations. When Elaine leaves, Rupert admits their suspicions are true and asks Eddie to kill “Abe.” Eddie is aghast, but a short while later, he drives “Abe” to the mountains under pretense of a hunting trip. At the hunting lodge, “Abe” unknowingly dons a wiretapped jacket given to him by Rupert, who listens in on “Abe” and Eddie while they hunt. Two gunshots ring out, and Rupert concludes that “Abe” is dead. A few days later, Rupert’s actors meet in the tycoon’s office for their final payment. Rupert asks them to attend “Abe’s” memorial service at the Fielding brewery that afternoon as a final performance. At the funeral, Eddie confronts Rupert about the scam. Just then, the guests hear yodeling from the casket, alerting them to the fact that “Abe” is still alive. As “Abe” rises from his deathbed, Rupert claims he is an impostor, but the actors turn against Rupert and pretend that George is really “Abe.” A chase ensues through the brewery and Rupert pushes “Abe” into a brewer’s vat. However, Eddie follows and hits Rupert over the head with a bottle, rescuing his friend George. Finally able to tell the truth, George announces that his true name is “George Washington.” Everyone would rather believe he is Abe Fielding, the proper inheritor of the brewery fortune. Elaine and George get married, and George and Eddie agree to be friends forever.