An Esper with transcendent abilities lives in constant danger of losing control every time he uses his powers. In this world, only a Guide can soothe and stabilize an Esper on the verge of collapse. Wonwoo, once a soldier and a newly awakened Guide in a war-torn world, loses all his comrades in a devastating battle. But when a mysterious, dense fog suddenly appears, he's pulled into a parallel world. There, he encounters a version of himself dying within the fog — and is given a chance to live on as that other self in this new world. “I hope you don’t live with regrets... or without purpose.” To his surprise, all the comrades who had died in his original world are alive in this one. Determined to protect them this time, Wonwoo visits each of them, using his abilities to help and support them. But in the process, he comes face to face with Gye-yoon, the ruler of the North. “It’s those eyes… Those eyes that look just like his.” And yet, every time he sees Gye-yoon... someone else keeps coming to mind.