Ellen “Ellie” Andrews is a spoiled heiress who has run away with King Westley, a pilot and fortune-hunter as opposed to the wishes of her incredibly rich father Alexander Andrews. Alexander wishes to cancel the marriage because he is aware that Westley is only after her money. Ellie jumps ship in Florida and elopes aboard a Greyhound bus to New York City to be with her husband. On her way, she meets Peter Warne, a fellow bus passenger who happens to be a newspaper reporter who just lost his job. Peter is able to make out her identity and makes her an offer: If she gives him an exclusive story on her, he will assist her in reuniting with her husband. However, if she does not cooperate, he would tell her father where she is and Ellie agrees to go through with the exclusive.
While the duo go on adventures together, Ellie begins to grow to like Peter and falls in love with him. They eventually come to a point where they need to hitchhike, and they both fail to secure a ride until Ellie shows off a shapely leg to Danker, the next driver. The pair stop on their way and Danker attempts to steal their luggage, but Peter chases him and forcefully takes his Model T. As they draw nearer to the end of their journey, Ellie tells Peter how she feels about him.
Later the motel owners notice that Peter’s car is missing, and they ask Ellie to leave. Ellie believes that Peter has deserted her, she makes a call to her father, and he grants her his permission to marry Westley. She concludes that Peter has decided to betray her for the reward money and gives her consent to having another wedding which would be formal. On the day of the wedding, Ellie tells her father the whole story. When Peter visits Ellie’s home, Alexander offers him the reward money; however, Peter insists that he only wants to be paid for his expenses, a small $39.60 for the things he had to sell to buy gas.
Ellie’s father attempts to question Peter’s true intentions to determine if he really loves his daughter and also have him explain his strange behavior, and Peter admits that he loves Ellie but storms out of the house. Westley shows at his wedding; however, Alexander tells his daughter how Peter had turned down the reward money and informs her that her car is waiting at the back gate just in case she changes her mind about getting married to Westley. Ellie leaves Westley at the altar and runs straight to her car and zooms off as the newsreel cameras crank.
Some days after, Alexander at work when he receives a call from Westley who tells him that he will be accepting the financial settlement he has been offered and would accept the wedding cancellation. Alexander’s personal assistant shows him a telegram from Peter that says: “What’s holding up the annulment, you slowpoke? The walls of Jericho are toppling,” as reference to a movable blanket wall strapped to a wire across the room they slept in to offer them privacy.
Alexander responds to the telegram with the annulment in his hands saying, “Let ‘em topple.” A final scene shows Peter’s old Model T parked in a motor court in Glen Falls, Michigan. The people of the motor court discuss, as they wonder why the newlyweds wanted a clothesline on such a warm night, along with extra blanket and the little tin trumpet he had gotten for them. As they observe what is going on in the cabin, the toy trumpet plays a fanfare and the blanket falls to the ground, as the cabin lights go off.