The story of Charles Darwin's great voyage on board the Beagle is a story of initiation and discovery. It remains one of the most significant scientific expeditions undertaken in history for it was during the voyage that Darwin developed his theory of evolution. This is the story of the journey, Darwin's personal transformation and the scientific revolution it ignited. The film investigates the scientific research and thought in the fields of geology, zoology and biology, which have been inspired by Darwin's discoveries. Contemporary scientists illustrate Darwin's thought process and research procedures and evaluate them in light of today's scientific findings.