Charlie Chan was a Chinese-American police detective created by author Earl Derr Biggers. The character first appeared in silent serials in the mid-1920s and as a secondary character in other movies. In 1931, Chan became the main character in what became the first of a 47-film series, with actor Warner Oland cast in the role. Although the character (who was portrayed by three different actors, all Caucasian) is now seen by some as racist, the films are an accurate depiction of the commonly perceived stereotypes of Asians during the 1920s, 1930s and 1940s. The four films in the "The Charlie Chan Collection Volume 4" feature the first appearance of Sidney Toler, who replaced Olund. Toler would play Chan for the next seven years before another actor took over the role in subsequent movies in the series.
In Sidney Toler's first appearance as the Asian sleuth, Charie Chan is a passenger on a freighter on its way to Honolulu. When the ship arrives, Chan discovers there's been a murder aboard the vessel, and orders its passengers to stay onboard until he can deduce which of them is the murderer.
In "Charlie Chan in Reno," the detective heads to Reno, Nevada, when an old friend is arrested for murder while visiting the city to obtain a quickie divorce from her husband. When Chan arrives, he discovers several people staying at the hotel who wanted the victim dead, so he must determine which of them is the guilty party and prove his friend's innocence.
Considered by fans of the series to be one of Toler's best performances as Chan, the detective looks into the suicide of a friend. As Chan investigates, he suspects a dodgy psychic who's working at the 1939 World Exposition on San Francisco's Treasure Island is the culprit. His suspicions are confirmed when he uncovers evidence that the psychic has a history of blackmail.
On the eve of World War II, Charlie Chan is in Paris for a reunion of his World War I buddies. His reunion is interrupted, however, when he is asked to investigate the murder of a munitions manufacturer who had plenty of enemies. While following leads, Chan uncovers a conspiracy involving smuggling arms to the Nazis.