Although Penelope Elcott's banker husband James is in love with her, he is constantly preoccupied with business. On a whim, Penelope disguises herself as a sweet old lady and holds up her husband's bank for $60,000. She then goes to the ladies' room, removes her disquise, emerges wearing a yellow suit, informs the guards that a little old lady with a gun is in the washroom, and leaves the bank. Afterwards, she goes to her mentally unbalanced psychiatrist, Gregory Mannix, and confesses her history of kleptomania. A concealed camera has photographed the crime and has caught a rear view of the yellow-suited woman leaving the bank. Police Lieutenant Bixbee begins to suspect Penelope when he notices that the little old lady and the yellow-suited woman in the film have the same walk as she does. Penelope disposes of the yellow suit in a thrift shop, and it is purchased by Sadaba, who runs a fashion boutique. Sadaba learns of the suit's significance, and she and her partner, Ducky, try to blackmail Penelope. Penelope confesses to Dr. Mannix, who attempts to return the $60,000 through the bank's night deposit box and, in his haste, leaves the cash exposed. Penelope confesses to her husband when a streetwalker who finds the money is accused of committing the crime. She is forced to take drastic measures to convince him of the truth of her story, but he refuses to press charges. Penelope reforms, having gained the renewed interest of her husband.