Charlie Chan (Warner Oland) is tired from traveling all over the world solving crimes. He decides it is time to go to Shanghai and take a vacation. However, before he can even unpack the local police are knocking at his door asking for help. James Andrews (Russell Hicks), an American spy, has discovered the existence of an international drug smuggling ring. They need Charlie’s help to infiltrate the ring and arrest all of the dealers. Lee (Keye Luke), Charlie’s son comes to the aid of his father. Together with Andrews the three thwart the drug smugglers, but Charlie still needs a vacation!