Ronan Nash is a former Space Corps Marine who just wants to enjoy civilian life with no one shooting at him-especially his ex wife. After a nasty divorce, he tries to work on his contentious relationship with his son Aiden. But when a devastating alien force invades the peaceful planet of Zeplovia, Ronan must once again pick up arms and venture into the fray. With his son trapped across the city, Ronan must battle hordes of ruthless Tarvaax to save him.