Gyeongseong, 1945. In Seoul's grim era under colonial rule, an entrepreneur and a sleuth fight for survival and face a monster born out of human greed.
Facing financial ruin, Jang Tae Sang agrees to track down a missing person — but two figures trail him. Meanwhile, sinister operations occur underground.
Yoon Chae Ok and Yoon Jung Won find a lead on Myung Ja, leading them to a hospital. Soon, a calamity traps the two inside, leaving Tae Sang concerned.
Tae Sang decides to reenter the hospital, but discovers that Ryu Sachimoto is nearby. At the hospital, Chae Ok and Jung Won devise a risky rescue plan.
Reunited in their search for Myung Ja, Tae Sang and Chae Ok attempt to also save other survivors. But soon, the monster makes itself known.
After coming face to face with the creature, Tae Sang and Chae Ok get captured. But as one plans his escape, the other stays to find a person dear to her.
Tae Sang steadfastly remains to save Chae Ok and the captives. On a mission to find her mother, Chae Ok learns the grisly truth — and confronts the beast.
With only 10 minutes to act, Tae Sang and Chae Ok risk it all to get everyone to safety. But just as all goes to plan, one of them may not get out alive.
An unlikely acquaintance becomes Tae Sang's ticket out of the hospital. After a touching reunion, Tae Sang and Chae Ok encounter a transformed Myung Ja.
After a series of grisly deaths, Ishikawa finds Myung Ja in her new state. Tae Sang shares a tender moment with Chae Ok, unaware of her hidden plan.
In order to rescue Chae Ok and stop the atrocity, Tae Sang and Jung Won forge a plan. But just as the coast seems clear, Yukiko Maeda stands in the way.
On a mission to clear his name, Jang Ho Jae searches for a mysterious woman. On the job, Chae Ok encounters a familiar person from decades ago.
While looking for the same person, Ho Jae ends up saving Chae Ok, who's being chased by a mysterious being. Ho Jae begins to wonder more about his past.
Chae Ok agrees to work with Ho Jae to find Seung Jo, but they soon find themselves in peril. Meanwhile, Chae Ok's monstrous instincts begin to surface.
Ho Jae tries to piece together everything that has been hidden from him. Chae Ok discovers that the atrocities of the past continue to the present day.
In his effort to save Chae Ok, Ho Jae makes a momentous decision. Having sustained severe injuries, they must battle through a treacherous escape.
After a test subject wreaks havoc in public, Jeonseung Biotech goes into damage control. Fate drives Ho Jae and Chae Ok to confront the company head-on.
As Ho Jae's enemy threatens to hurt those closest to him, he risks everything to protect them. Will he survive the ferocious beasts and save Chae Ok?
