Become the Villain (S01E04)

The initial vehicle is ambushed by a mysterious sphere, causing it to flip over. A soldier is killed instantly, and So-yeon suffers serious injuries. The students choose to exit the vehicle in search of nearby shelter. They soon discover an office at a construction site where they can take refuge and recuperate. Unfortunately, their brief moment of safety is short-lived. Meanwhile, Lieutenant Lee disobeys orders and takes a vehicle to go after the students.