In the 1840s, Ramsey MacKay, the driver for the struggling Wells Fargo mail and freight company, will secure an important contract if he delivers fresh oysters to Buffalo from New York City. When he rescues Justine Pryor and her mother, who are stranded in a broken wagon on his route, he doesn't let them slow him down and gives the ladies an exhilirating ride into Buffalo. He arrives in time to obtain the contract and is then sent by company president Henry Wells to St. Louis to establish a branch office.

In Vienna, a new jazz club featuring American trumpeter Buzzy Bellew threatens the existence of its neighbor, the Waltz Palace, run by Franz Strauss and featuring his granddaughter, singer Elsa. Smitten by Elsa, Buzzy hides his identity and association with the club -- whose owner intends to buy out the Palace property. When Elsa accidentally learns who Buzzy really is, it appears he may have to return to America alone.