Rex, trained from youth by a brutal warlord, is a former assassin turned bounty hunter. In his desire to rectify a lifetime of murder of abuse, he receives a mission to rescue a woman from captors, captors from the very faction who once raised him to be a ruthless murderer. Once he rescues Lynn, he quickly learns she holds a mysterious secret that compels both his current employer and past faction to compete for possession of her. As they travel together across the world, their relationship deepens. A simple rescue mission escalates into a quest to save, or perhaps, destroy the world. Together, Rex and Lynn must learn to be unstoppable, or together they may fail the world.