In 1947, the world is gripped with excitement as the young Norwegian adventurer Thor Heyerdahl embarks on an astonishing expedition - a journey of 4,300 nautical miles across the Pacific Ocean on the Kon-Tiki raft. From his days living in the Marquesas with his wife Liv, Thor suspected that the South Sea Islands had been settled by ancient South Americans from thousands of miles to the east. Despite his inability to swim and fear of water, Thor decides to prove his theory by sailing the legendary voyage himself.