Cloud Atlas is a 2012 science fiction film written and directed by the Wachowskis and Tom Tykwer. Based on the 2004 novel by David Mitchell, it has multiple plots occurring during six eras and features an ensemble cast who perform multiple roles across these time periods. The film was produced by Grant Hill and Stefan Arndt, in addition to the Wachowskis and Tykwer. During its four years of development, the producers had difficulties securing financial support.