In the coming future, the Adam Pharmaceutical Co., Ltd., conspiracy, orchestrated the release of the Adam Virus, turning people into zombies as it spread. Only three unified countries in the world remain.

Following the unexpected death of one of the virus vaccine developers Dr. Oh, a major in the Rainbow City of the United Nations, Kwak Soohwan, is tasked with retrieving Seok Hwa, a senior researcher living in seclusion on Jeju Island, and is to bring him back to Seoul. Later in Seoul, in the Yeoudio Shelter, Soohwan took guard as Seok Hwa took over Dr. Oh’s research to continue developing a vaccine.

With the Adam Virus mutating a countless number of times slowing down the development of a vaccine, the attacks on Rainbow City from the resistance, a group of rebels rejecting the tyrannical regime, only intensifies. In a time of turmoil, Seok Hwa questions the City’s policy focus on developing a vaccine but not a cure, and as a result, Kwak Sohwan and Seok Hwa develop more and more animosity....