VIDEO : Details Revealed For 'Supergirl' Season 4

According to Supergirl showrunners Robert Rovner and Jessica Queller, the final moments of Monday night's season 3 finale sets up a major DC Comics storyline for the show's fourth season. The finale saw Melissa Benoist's Supergirl travel back in time to defeat the villain Reign. However in doing so, an alternate version of Supergirl then arrived on Earth in the aftermath. In comments to comicbook.com, Rovner explained, "For fans of the comics, I think they might recognize that the story we want to tell is inspired by the iconic DC Comics? Red Son, which told an alternate origin story for Superman."