Set sometime after the events of Zack Snyder's Justice League, Clark Kent is trying to reestablish himself and pick back up from where he left off though knowing the world has undeniably changed since he was last around while also coming to grips with soon becoming a father. But things are about to become much complicated for him as a mysterious figure suddenly arrives in the form of a young female Kryptonian who Clark discovers is, in fact, his cousin named Kara Zor-El. As Clark attempts to become a mentor figure for Kara and struggles to teach her anything he knows, she warns him that she is desperately trying to escape the wrathful control of a powerful and sinister extraterrestrial android and a sworn enemy of the Kryptonian species who calls himself Brainiac, and since her arrival, he will be coming for Kara and will take Earth along with.