1x1 - Question the Spheres

March 31, 2023

For a year, people learn to live with the spheres without suffering any specific changes. Even with the alien-looking spheres floating all over the sky, the CSAT is what matters the most to seniors of Sungjin High School. When the exam is just around the corner, one of the spheres drops on a military camp for the first time, and more shocking news awaits them.

1x2 - Military Training Begins

March 31, 2023

After spheres from the sky drop to the ground, military training begins for the students to ensure their safety. However, the students find it too demanding and have a difficult time. As students head to the shooting range to learn how to shoot, they get caught off guard and fall into a crisis. Meanwhile, a student gets killed by one of the spheres.

1x3 - School Escape

March 31, 2023

Two people from Class Two die. To prevent chaos, this news is not yet known throughout the entire school. After their deaths, students of Class Two get sick of all the hardcore training and try to escape school to go back to their homes. However, all their attempts go to waste and the biggest attack of the spheres begins.

1x4 - Become the Villain

March 31, 2023

The first vehicle gets attacked by a sphere and turned over. The soldier dies on the spot, and So-yeon gets badly injured. The students decide to leave the vehicle and find a shelter nearby. Soon, they find a construction site office where they can hide and rest. However, their peace doesn’t last long. Meanwhile, Lieutenant Lee goes against the order and steals a vehicle to rescue the students.

1x5 - Will We Ever Go Home?

March 31, 2023

Chun-ho tries to make sure that the kids all survive so they can return safely to the camp. The kids after having gone through a common struggle begin to bond with each other. They also begin to learn more things about being a soldier. But there seems to be a more ominous order awaiting them from high command. Will they make it through another day?

1x6 - Fight Or Flight

March 31, 2023

After a heated encounter with the spheres, the group picked up some survivors. However, the heavily traumatized survivors have a hard time blending in and coping with the situation. Their outbursts and dire situation make the group rethink their morals and imperatives. Will they carry on with the mission or will they flee for their own safety?

1x7 - Disagreement Among Classmates

April 21, 2023

Children in Class 3-2 who have become accustomed to both the sphere and death. I find laughter again, but I didn't know that a crack was forming in it. Along the way, he meets strangers who ask for help.

1x9 - For Whom the Bell Tolls

April 21, 2023

While trying to save Bo-ra, Soo-chul sacrifices himself. Everyone wonders what they should do with his body when suddenly someone mentions that Soo-chul rigged voting. After finding out the truth behind the voting, they break into a fight. Then they find out why Soo-chul had to manipulate votes, which comes as a shock.

1x10 - End of the War

April 21, 2023

After aborting the mission, the kids walk for days but get to nowhere. However, they reach an amusement park and have fun as if it is their last. Meanwhile, Yeong-soo is not comfortable about walking away from the mission as he still believes the CSAT is not canceled. The end of the war draws near, but the kids have a long way left to survival.

1x11 - Episode 11

April 28, 2023

1x12 - Episode 12

May 5, 2023

1x13 - Episode 13

1x14 - Episode 14

1x15 - Episode 15

1x16 - Episode 16

1x17 - Episode 17

1x18 - Episode 18

1x19 - Episode 19

1x20 - Episode 20