Charlie Chan at the Olympics (1937)

When an experimental plane is hijacked and its pilot murdered, the new guidance system that will allow it to fly unmanned is stolen. Charlie traces the strategically important invention to the current summer Olympic games in Berlin, where myriad spies, enemy agents, and hard-core criminals are ruthlessly pursuing it in order to sell it to another government. Charlie's son Lee, a member of the U.S. Olympic Swim Team, is on hand to help his father recover the device and solve the mystery.