“Defiance” is a U.S. sci-fi TV series set in a future where Earth has been dramatically altered by the arrival of alien species. The storyline centers on Joshua Nolan, who serves as the law enforcement officer in the town of Defiance, a place where humans and intelligent aliens live together. The series explores the lives of Nolan, his adopted alien daughter Irisa, and Amanda Rosewater, the newly appointed mayor of the town.