Su-ji and Ja-eun continue to search for allies in their quest to eliminate the Pyramid Game. Unable to convince their classmates, they look for options outside of the school, like hacker Cho Seung-hwa. A bullied girl searches for a way out.

Su-ji finds trouble when a classmate reaches a breaking point on parent visitation day. Ha-rin sends a warning when Su-ji loses Ha-rin's vote. Su-ji's plans gradually fall apart thanks to a friend's betrayal. The 15th game brings an unexpected twist.

A shocking reveal after the 15th game disrupts the class rankings, and prompts complaints from students about flaws in the voting app. Ha-rin has a plan to restore order. A savage game of dodgeball works to Ha-rin's advantage...until the ball stops.