One day, Hotchkiss Falls, New York soda jerk Peggy Evans becomes so bored and unhappy with her life that she bets her co-worker, Mitzi, that she can serve ice cream sundaes with her eyes blindfolded. Although Peggy correctly dishes up the customers' requests, she is caught in the act by Bob Stuart, the store's new general manager, who angrily orders her to his office. Upon seeing the attractive Peggy unmasked, however, Bob quickly softens toward her and tries to cheer her up. Instead, Bob makes Peggy more agitated, and she storms out of his office. Later, after Peggy leaves what appears to be a suicide note at her boardinghouse and then disappears, Bob is accused of driving her to suicide. Unknown to all, Peggy actually has fled to New York City and has resolved to shed her old identity in favor of a more glamorous one. To that end, Peggy spends her life savings on a beauty makeover, changing her hair from brown to blonde and her clothes from plain to flashy. While standing outside the Morning Star newspaper office, however, the reborn Peggy accidentally is struck by a paint can and knocked unconscious. When she awakens inside the office of Star publisher Durstin, Peggy is horrified to discover she is covered in paint and tearfully tells Durstin that she has no name or address. Durstin assumes that Peggy has amnesia and, anxious to avoid a lawsuit, puts her up at his house and runs a photograph of her in his paper. After Durstin casually suggests that she might be a kidnapped heiress, Peggy searches the public library's newspaper stacks for long-lost heiresses to impersonate. Peggy finally comes across a story about Carol Burden, a little girl who was kidnapped seventeen years before and never found. Bob, meanwhile, is fired from his job after all of his employees go on strike to protest the store's treatment of Peggy. While pleading with his boss, Bob notices Peggy's photograph in the Star and recognizes her, despite the makeover. Determined to prove that Peggy is alive, Bob rushes to New York, while at the same time, Peggy reports to Durstin that she has suddenly recalled the name "Baba." Durstin determines that "Baba" is the name of the Burdens' nursemaid and declares that Peggy is Carol. Carol's sour-faced father Cornelius, however, is suspicious of Peggy and threatens to prosecute her if she is lying. Fearful, Peggy tries to back out of her impersonation, but Cornelius insists on taking her to his mansion to prove her claims. While waiting to meet the elderly Baba, Peggy happens to see the nursemaid and Cornelius remove a small object from a safe. Peggy is then asked to identify Carol's favorite toy from among a roomful of toys, and after some clever deductions, picks the correct one. Now convinced that Peggy is his long-lost daughter, Cornelius cries for joy. Later, Bob, having read about Cornelius' happy reunion in the Star , sneaks into the Burden mansion and tries to see Peggy, but is knocked out by Jimmy, Cornelius' bodyguard. Bob then reads that Peggy is going to attend an upcoming concert and, during the performance, calls out her real name from the balcony. His yelling causes an uproar, and he almost falls over the balcony during the ensuing commotion. After the concert, Bob sees Peggy at a café and once again loudly calls her name. Without thinking, Peggy responds to her name, but before Bob can confront her, Jimmy slugs him again. Although Peggy eludes him, Bob succeeds in lifting her fingerprint from a rubber plant urn. Later, at Peggy's coming-out party, Bob again sneaks into the Burden mansion and surprises Peggy on the dance floor. When Bob declares that Peggy is his wife, Cornelius demands an explanation. Bob shows Cornelius a marriage certificate with Peggy's lifted fingerprint on it and states that she has had amnesia for as long as he has known her and, consequently, he knows nothing about her childhood. While insisting that she has no memory of Bob, Peggy convinces Cornelius, whom she has grown to love like her own father, to allow her to go to Hotchkiss Falls to make her own determinations. On the way, Bob confronts Peggy with her deception, then informs her about the trouble she has caused him. Peggy persists in her impersonation, however, and while stopped at an all-night restaurant, sabotages his car. Peggy then connives to spend the night at the neighboring motel, calmly playing the role of Bob's long-lost wife. When pressed to join Peggy in bed, Bob finally confesses his deception, adding that she must indeed be Carol because Peggy never would have had the courage to trust him. Bob calls Cornelius to pick up Peggy, unaware that Cornelius has just received damning information about her. After Cornelius nonetheless agrees to drive to the motel, Peggy, realizing that she has fallen in love with Bob, admits her deception to him. Bob is at first angry with Peggy, but by the time Cornelius and Baba arrive, has forgiven her and tries to stop her from telling all. Although now sure that Peggy is an impostor, both Cornelius and Baba ask her to go on as Carol, and she happily agrees. Bob then proposes to Peggy, and Cornelius looks forward to becoming a father-in-law.