Will you remain a monster or a human being? A world where desire becomes a monster. Hyun-soo and the survivors of the Green Home, who are fighting their own battles to survive in their new home away from the Green Home, And the emergence of another being and mysterious phenomena that are unknown.
Cha Hyun-soo continues to fight as a special infected person and tries to sacrifice himself to make a vaccine. Songgang fights against a monster that recalls his past memories, and in this process, Songgang regains his past memories and stops fighting the monster. In the process, scientist Oh Jung-se shows enthusiastic interest in Songgang. Meanwhile, Pyeon Sang-wook is taken away by Jeong Eui-myung, and Lim is trying to study it and siphon off the vaccine. At the Bamseom Special Disaster Base, soldiers struggle for survival by fighting monsters. Lim explores the possibilities of new humans by studying monsterization. Lee Kyung-eun gives birth to a monster, and the daughter has special powers.
The daughter turns Lee into a monster, and eventually Hyun-soo and Metaphor try to stop him. Metaphor goes through danger with Hyun-soo, and the child has the power to control the people who turn into monsters. The story unfolds as he searches for his brother, Eun-hyuk.
