Hyun-su wakes up to find Sang-wook, who has a new goal for them. Lee Eun-yu and Ji-su escape a violent evacuation and commandeer their next destination.

Eun-yu finds a hint of Eun-hyeok’s fate at a stop in her journey. During an experiment, Hyun-su finds that he has a special effect on another monster.

On a mission to find her husband, Yi-kyung makes a shocking discovery. The battered Ji-su and Eun-yu arrive at a new shelter, but catastrophe awaits them.

The survivors take shelter underground, where supplies run low. In her continued search for Eun-hyeok, Eun-yu encounters a young girl.

Sergeant Kim and Master Sergeant Tak clash on how to protect their men. The mysterious girl approaches Eun-yu with an enticing offer.

Eun-yu chases Yi-kyung and the girl, with Park Chan-yeong right behind her. The death of survivors and a missing soldier throws the stadium into unrest.

Eun-yu shares a terse reunion with Hyun-su. While the platoon embarks on their search for a missing soldier, the stadium experiences a monster threat.

As Yi-kyung faces death, the young girl tries to save her. In the ruins of the lab, the soldiers discover other survivors who aren't what they seem.

Hyun-su gives it his all to bring Yi-kyung’s humanity back. Sergeant Kim faces countless monsters in an effort to make it out alive with his men.

Resolved to find his child, Jung Ui-myeong heads to the stadium. Despite Hyun-su's unpredictability, Eun-yu tries to wake him up during a sudden crisis.

Yi-kyung discovers Ui-myeong's true motive for him and their daughter. Eun-yu accepts a challenge from Hyun-su's alter ego and heads to the stadium.

The girl contemplates her future with Yi-kyung — and a life away from Ui-myeong. Sergeant Kim encounters Eun-hyeok, who reveals a new kind of being.

Eun-hyeok's reunion with Hyun-su and Eun-yu turns into chaos. Ui-myeong prepares for his body transfer, while Sergeant Tak carries out his own plan.

In her trek to the stadium, Eun-yu begins to feel a personal worry. While Ui-myeong searches for the girl, she plans a counterattack in the background.

Hyun-su and Eun-hyeok arrive at the stadium, splitting up to find Ui-myeong. During the great escape, Sergeant Tak commits the ultimate sacrifice.

In the final battle, Hyun-su and Eun-hyeok confront the girl head-on — getting an assist from an old friend. Will they finally succeed?