Fact: Tom Cruise's cousin William Mapother has become the ninth former Lost star to sign on for Hawaii-based cop drama Hawaii Five-O. Mapother, who played Ethan Rom on Lost, will guest star in an upcoming episode of the drama, which features his former co-stars Daniel Dae Kim and Jorge Garcia as regulars. Other Lost stars who have made their way back to Hawaii for the police series include Henry Ian Cusick, Terry O'Quinn and Tania Raymonde.