The fugitives Burke, Virdon and Galen try to save the life of a human blacksmith and his son, whome gorilla leader Urko has threatened with death should his horse lose another race. The trio also attempt to expose a crooked gorilla by framing him in a plot to kill Urko. [The third of five telefilms edited from episodes of the 1974 TV series; this film combines the episodes "The Horse Race" and "The Tyrant"]