In the show’s tenth season, Sam and Dean Winchester faced their most personal threat yet. The all-powerful Mark of Cain threatened to consume Dean, turning him into one of the monsters he has spent his life hunting. Meanwhile, a formidable witch, Rowena, rose to power to claim her position at the right hand of the King of Hell, Crowley. Once Rowena revealed herself to be Crowley’s mother, the King was forced to choose between his family and the Winchesters, all while Sam, with the help of fallen angel Castiel, Crowley and some unlikely allies, waged a desperate battle to save Dean from the Mark of Cain.