Mr. Wong in Chinatown (1939)

A young woman (Lotus Long) turns up at Mr Wong's (Boris Karloff) home asking to see the famous detective urgently. However before she can see him she is bumped off by a poison dart. Wong and Inspector Street (Grant Withers) begin the investigation with only a vague clue to start with, perky reporter Roberta Logan (Marjorie Reynolds) to help/hinder...

The murdered woman, Princess Lin Hwa, was on a secret mission to buy warplanes for the Chinese government. The investigation soon turns up a masked man who was keen to stop her and won't stop at one murder... and Mr Wong himself is soon in the firing line.

The film is a bit slow, it's not the best in the Mr Wong series though Karloff was always good value as Wong.