princess mei ling visit charlie chan house with need of the great detective help . before she can meet with him she be kill by an air gun and but be able to scrawl capt k on a sheet of paper in hop to give chan a clue to her killer . chan and team up with police sergeant and bill davidson and find the apartment where the princess be reside and find that her trip to america be to purchase a fleet of airplane to aid in china defense from invader . captain kong and who be captain of the ship that the princess travel on and and captain kelso and who be the supplier of the plane for the princess and be both determined to see that chan and davidson make no further progress on the murder case and which have also add the princess maid and a mute chinese boy who may have see the killer . obviously by the time the monogram chan film be at this stage they be pretty routine and boring and this film be no exception and despite be roland winter debut a chan . the film really lack a mystery aura a see in any other chan film with a storyline that do little in the way of entertain . victor sen yung last the least to do of any son in any chan film and moreland lack much of the humor he usually do and but do seem more involved with solve the case . rating and 3 .