King of the Congo (1952) was the 48th serial released by Columbia Pictures. Based on the comic book character "Thun'Da, King of the Congo", created by Frank Frazetta.
The film series is a complicated serial with more twists than a maze that basically centers around a U.S. Air Force captain and his quest for missing microfilm that contains vital information. The heroic Buster Crabbe plays Captain Roger Drum, who shoots down an enemy plane on its way to Africa with the secret microfilm. Intent on revealing the subversive group that the message was for, Drum assumes the pilot's identity and flies to Africa himself and crashes in the jungle. He is rescued by the pacific Rock People, led by Princess Phi (Gloria Dea), and is renamed Thunda, King of the Congo, after he rings a temple gong in alarm. With the subversives believing Thunda is their missing pilot and under constant attack by another tribe called the Cave Men, our hero plots to bring down the subversives who are searching for a new metal more radioactive than uranium. At the end, Thunda (or Drum) clear the jungle of villains and reunites the Rock People and Cave Men for well.
King of the Congo also was the seventh and last serial starred by Buster Crabbe between 1933 and 1952.