In the year 2046, it's a new Earth - with new rules. Over thirty years after various alien races arrived on Earth, the landscape is completely altered, terraformed nearly beyond recognition. To the town of Defiance, on what used to be St. Louis, comes the mysterious Nolan (Grant Bowler) and his charge, Irisa (Stephanie Leonidas). As they settle into town - overseen by the mayor, Amanda Rosewater (Julie Benz) and filled with residents like the powerful Rafe McCawley (Graham Greene), enterprising lounge owner Kenya (Mia Kirshner) and the ambitious, alien Tarrs (Tony Curran and Jaime Murray) - events begin to unfold that threaten the fragile peace this border town has fought for.