When Chan's oldest son, Lee (Keye Luke), is chosen to compete in the Olympics, Chan is proud as can be. Meanwhile, over the skies of Chan's Honolulu, the "Hopkins plane" is demonstrating an improvement of remote radio control to the US military. However, the aircraft is hijacked by a concealed stowaway, the device stolen, and the test pilot murdered. When Chan, followed by his astute second son, Charlie Jr. (Layne Tom Jr.), tracks down the stowaway, he finds only the man's body.