Princess Mei Ling visits Charlie Chan's house with need of the great detective's help. Before she can meet with him she is killed by an air gun, but is able to scrawl "Capt K" on a sheet of paper in hoping to give Chan a clue to her killer. Chan, teaming up with police sergeant, Bill Davidson, finds the apartment where the princess is residing and finds that her trip to America was to purchase a fleet of airplanes to aid in China's defense from invaders. Captain Kong, who was captain of the ship that the princess traveled on, and Captain Kelso, who was the supplier of the planes for the princess, are both determined to see that Chan and Davidson make no further progress on the murder case, which has also added the princess' maid and a mute Chinese boy who may have seen the killer. Obviously by the time the Monogram Chan films were at this stage they were pretty routine and boring and this film is no exception, despite being Roland Winters debut as Chan. The film really lacks a mystery aura as seen in any other Chan film with a storyline that does little in the way of entertain. Victor Sen-Yung last the least to do of any son in any Chan film and Moreland lacks much of the humor he usually does, but does seem more involved with solving the case. Rating, 3.