Twenty-eight-year-old Jeannie MacLean is a resident of the small Vermont town of Heatherdale. Since her thrifty grandfather's death, Jeannie has been forced to take in neighbors' washing in order to support herself. However, after the Reverend MacDonald delivers a letter her grandfather left for her, Jeannie discovers his will leaving her almost five thousand dollars. Jeannie immediately decides to spend the money on a visit to Scotland to see the Edinburgh Festival, but the only reservation she can get at the last moment is on an Air France flight to Paris. On board the plane, she is seated next to Stanley Smith, a washing machine inventor from Boise, Idaho, who is hoping to sell the European rights to his invention to a businessman in Paris. When they arrive in Paris, they go their separate ways, but after Stanley learns that Mr. Fielding, the man he needs to see, is on his honeymoon in Edinburgh, they meet again on the train to Edinburgh. After a mix-up with Jeannie's boardinghouse reservation leaves her without a room, she goes to the posh hotel where Stanley is staying to see if he can help her. While Stanley tries to arrange a room for her, Jeannie is approached by impoverished Lord James MacNairn, who is under the impression that she is an American millionairess. Jimmy is reduced to living in two rooms of his family's castle and needs a wealthy wife to restore the castle and his family's fortunes. After Stanley secures the hotel's bridal suite for Jeannie, they arrange to go out that evening. However, Stanley, who admits to a fondness for glamorous, red-haired women, meets Helene, a French fashion model, and breaks his date with Jeannie as Helene is available only that evening. The next day, while Stanley pursues Mr. and Mrs. Fielding to St. Andrews, Jimmy shows Jeannie around Edinburgh and invites her to a ballet. Jeannie then buys an elegant evening gown for the event, unaware that Stanley has arranged tickets for them to attend a different event. When they meet by chance in the lobby, Stanley thinks she is going out with him, but she tells him that she has a date with a gentleman and accuses him of lying to her. Stanley and Helene follow Jeannie and Jimmy to the ballet and later dine separately in the same restaurant. Jeannie is enchanted by Jimmy and over the next few days, while Stanley and Fielding negotiate, Jimmy shows Jeannie more of Scotland's scenic beauty, including Loch Lomond and his nearby castle. Later, when Stanley learns from the hotel's page boy that Jeannie is finally alone, he becomes distracted while signing the documents on the deal with Fielding, and leaves to find her. However, Stanley encounters Jimmy instead and tells him to abandon the chase. At dinner that evening, when Jeannie tells Jimmy that she is leaving the next day, he asks her to marry him. Stanley interrupts them to announce that he has sold the European rights to his washing machine and Jeannie informs him that she and Jimmy are engaged. After Stanley leaves, Jeannie tells Jimmy that they will have to wait to get married until he has some money, as all of hers is gone. Jimmy explains that he thought that she was a millionairess and that he is totally broke. However, he adds that although he originally wanted to marry Jeannie for her money, he now wants to marry her for herself. Jeannie tells Jimmy that she likes him, but not enough to marry him. After Jeannie sails back to the United States, she sells the house in Heatherdale and prepares to move to New York. As she is packing, Stanley shows up and shows her a newspaper story about Jimmy's engagement to a toothpaste heiress. Stanley tells her that he loves her and, when he asks her to marry him, she agrees.