Westworld is an American dystopian science fiction Western television series. It is based upon the 1973 film of the same name written and directed by Michael Crichton and loosely upon its 1976 sequel, Futureworld. The story begins in Westworld, a fictional, technologically advanced amusement park populated by android "hosts" The series' setting expands to the real world, in the mid-21st century, where people's lives are driven and controlled by a powerful artificial intelligence named Rehoboam. Westworld's debut on HBO had the network's highest viewership ratings for a premiere since True Detective in 2014.