Professor Indiana Jones is about to lecture the Pennsylvania History Society when some trouble with his microphone stand leads him off into recounting a disastrous spy mission in which he was involved in May 1917. Jones had joined up with an international trio of spies plotting against their German counterparts in the neutral city of Barcelona. After his old acquaintance Pablo Picasso helped him get a job at Sergei Diaghilev's Ballets Russes, Indy devised a plan to forge a love letter written by the German cultural attaché to make it seem the man was having an affair with the Countess of Toledo.

Wyoming, 1950. Indiana Jones and his friend Grey Cloud have obtained a sacred ceremonial pipe and end up in a snow-logged cabin. When Jones finds a soprano sax, he is reminded of his college days in Chicago 1920. Indy was waiting tables at Colosimo's and had become obsessed with Jazz music. He managed to befriend Sidney Bichet who encouraged him to practice the soprano sax. But then Colosimo was murdered on the doorstep of his restaurant and Indy got caught up in the investigation together with his roommate Eliot Ness and young reporter Ernest Hemingway.