Charlie Chan (Roland Winters) and Number One Son, Lee (Keye Luke), are passengers aboard a commercial airliner headed for San Francisco. Also on board are two insurance couriers who are carrying a shipment of $250,000. Minutes after drinking coffee that was served, everyone on board the plane falls asleep, including the crew. Lee is the first to awaken and he notices a limp hand protruding from the cockpit door. A closer look reveals that one of the couriers has been stabbed to death and that the insurance money he was carrying is missing. After the plane safely arrives, Chan and son, along with assistant, Birmingham Brown (Mantan Moreland), take on the case.