Aluminum magnate James J. Maloney, Sr. meets with government officials to discuss the war effort and the need to end price-fixing. After the meeting, Maloney receives word that his son Jimmy, a playboy turned Army flight instructor, is lost with his navigator, Scully, somewhere in the Ozarks. While Maloney rushes to find his son, Jimmy and Scully crash land in the small town of Weaverville, where the mayor and his wife, Abner and Elviry Weaver, are trying to impress upon the citizens that they are better off in the mountains than in the big city. Taken with Susanna, Abner and Elviry's daughter, Jimmy pretends to be wounded so that she will tend to him. Maloney eventually arrives on the scene with his secretary, Doolittle, and while collecting Jimmy, discovers that Weaverville sits upon a rich deposit of bauxite, from which aluminum is made. Back in New York City, Maloney schemes to gain control of the land, on which he can make a huge profit, even though he knows he should turn it over to the government. Maloney invites the Weavers to the city, where he intends to get them accustomed to city ways. Using Jimmy as bait, Maloney also hints that his son will marry Susanna, thereby uniting the families. Although Maloney gets the Weavers drunk at a nightclub, Abner still refuses to sell Weaverville. Jimmy arrives, and not recognizing Susanna in her evening gown, takes her back to his apartment with the intention of romancing her. It becomes obvious to Susanna that Jimmy does not know who she is and that he is a Lothario. Brokenhearted, she returns to Maloney's house, and the angry Weavers go back to the Ozarks. Jimmy is also angry at his father, for he now realizes that he loves Susanna and wishes to marry her. Jimmy then informs the government about the bauxite to forestall his father's attempts at wartime profiteering. Still trying to get the land, Maloney hires actors to trick the citizens of Weaverville into believing that the government surveyors are a bunch of thugs who will kick them off their land. Despite Abner's pleas that they must be patriotic, the hillbillies prepare to fight for their homes. As they are discussing the situation, they hear gunfire in the valley below. Unknown to the Weavers, the Army is conducting training maneuvers, but the hillbillies mistake the war games for a real battle. Arming themselves with old rifles, pitchforks and dynamite, the denizens of Weaverville attack the side they believe to be the enemy. Jimmy, who is flying overheard, sees his father's fake surveyors attacking the hillbillies, and bails out. He is wounded by one of the thugs, but is able to warn the others in time that it is merely maneuvers they are witnessing. After the chaos ends, General Tobin tells Abner that it was an understandable mistake, and the hillbillies agree to give the government their land. Maloney, ashamed of his greed and poor patriotism, gives the Weavers land to build new homes, while Jimmy and Susanna kiss to seal their reconciliation.