Charlie Chan in Rio is a remake of 1931's Black Camel, one of the few pre-1934 "Charlie Chan" entries still in existence. While the original film was set in Hawaii, the remake takes place in Brazil, but the basic intrigues remain the same. While vacation in Rio de Janeiro with his son Jimmy (Victor Sen Yung), Honolulu detective Charlie Chan (Sidney Toler) is asked by the local constabulary to help solve a double homicide. The motivation behind the two murders is apparently tied in with sinister psychologist Alfredo Marana (Victor Jory), who utilizes hypnotism as an adjunct to a clever blackmailing scheme. Cobina Wright Jr. shows up early on as one of the murder victims, alongside Jory, Mary Beth Hughes and the ubiquitous Harold Huber, cast as a foreign police official. Hamilton Macfadden, who directed the original Black Camel, shows up as one of the suspects in Charlie Chan in Rio.