In the aftermath of World War II, the United States Military assigned a tech savvy GI named Jack Mullin the mission of investigating secret inventions left behind by the Nazis. Mullin’s journeys around Germany led him to a makeshift radio studio that had a device called the Magnetophon, the first reel-to-reel tape recorder that realistically recorded sound. After overcoming numerous obstacles, Jack Mullin managed to ship two machines back home to San Francisco. When he was released from military service, he demonstrated the Magnetophons for all the movie studios in Hollywood but faced rejection from each one. Eventually, a famous crooner gave him a shot and invited Mullin to a trial by fire audition that would change recorded sound forever.