Undercover High School

After an operation turns bad, Hae Seong and his team take on an unbelievable assignment to make things right.

Hae Seong investigates the old building at the school while he struggles to deal with school bullies.

Hae Seong digs into the school's ghost stories to find the gold, while Tae Soo's bad habits cause chaos.

Hae Seong avoids getting expelled and joins the student council to uncover secrets about a clock.

Miraculously, Hae Seong gets accepted into the student council, but Su A's suspicions threaten the mission.

Hye Seong learns the hidden truth behind the undercover mission. He leaves the team to get away from it all.

Su A joins the NIS team as an honorary field agent to help uncover the secret of the third ghost story.

Hae Seong pulls back after learning about a possible mole, but Su A pulls him back with shocking news.

Su A recovers in the hospital as Hae Seong exposes the grade-rigging scheme, throwing the school into turmoil.

Seo Myeong Ju returns vengefully, vowing to eliminate anyone in her way, especially Hae Seong.

Hae Seong discovers his father was murdered and follows clues leading to Director Kim, whom he confronts alone.

Hae Seung evades the police with the help of the team and Su A, while Chairwoman Seo takes drastic measures.