A ape is hunted in the jungle and taken to a big city, where he is kept in a zoo and forced to perform monthly for a local circus. Many years pass, and a ape, now aging, decide to break out and take their revenge on the kind-hearted plumber and his girlfriend who were hired by the circus to mind the apes. This sends the plumber through construction sites and through the sewers as the apes cause havoc, but soon, our favorite hero are forced into a truce when an even deadlier threat emerges from the city's underbelly.
