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.
Genres: Action & Adventure , Drama , Sci-Fi & Fantasy
Keywords: action , alien-invasion , apocalypse , based-on-webcomic-or-webtoon , high-school , leadership , military , monster , science-fiction , supernatural-phenomena , survival , thriller , war , watch-Korean-drama-online , tv-shows-online