He wakes up to find himself with amnesia in a past he wasn't even born into yet, and he has grown twenty years older, not knowing where or how he spent them. Before he can regain his memory, he is surprised to find that he is being pursued by two warring time groups, who are using time and its paradoxes to achieve a mysterious goal. He sets out to explore his new reality and realize the truth about his lost years. He finds himself lost in the midst of a fierce temporal battle, raging for more than a century, to solve a difficult "space-time" puzzle and uncover the secret of "Traveler Zero," the "origin" that began and ended everything. Who will reach "Traveler Zero" first and control the course of the flow of time?