A monkey escapes from a ship sailing up the Thames. Its flight into the wilderness of the big city becomes a disaster for some people, especially for Adam Burden, the future director of the world-famous zoo. However, it is not a disaster for Madalene, Adam's beautiful young wife. When she discovers that Adam is about to drill into the monkey's skull, she decides to save the animal. This marks the beginning of an adventurous escape for the two and an unusual love story.