Undercover High School, the gripping K-drama starring Seo Kang-joon and Jin Ki-joo, continues to escalate the tension as episodes 7 and 8 take viewers deeper into the mysterious world of Jeong Hae-seong, an undercover NIS agent disguised as a high school student. His mission to infiltrate the school and uncover a secret conspiracy takes an unexpected turn when his suspicious homeroom teacher, Oh Su-ah, gets involved.
In these latest episodes, the duo embarks on their first mission together, uncovering shocking truths about Seo Myeong-joo, the school’s powerful director. As they navigate hidden puzzles, secret files, and a dangerous game of deception, Jeong Hae-seong must also come to terms with his past and find someone he can trust. Meanwhile, tensions rise among the students as conflicts over academic corruption and secret agendas start to surface.
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As the mystery deepens, Jeong Hae-seong and Oh Su-ah are forced to rely on each other, blurring the lines between duty, trust, and personal connections. With conspiracies unfolding at every turn, the latest episodes prove that no one in this school is safe from the truth.
Undercover High School Episodes 7 & 8 : Oh Su-ah Joins Jeong Hae-seong’s Mission
Episode 7 kicks off with Oh Su-ah making a bold decision—she chooses to assist Jeong Hae-seong and the NIS team in solving the third legendary mystery of the school. Despite Jeong Hae-seong’s protests, she insists on proving that she can protect her students, just as much as any agent. Their first joint task takes them to Seo Myeong-joo’s office, where they play the piano in search of hidden clues. However, the investigation seems to hit a dead end when a mysterious key produces no sound.
Just as they are about to abort the mission, Jeong Hae-seong stumbles upon a startling revelation—Seo Myeong-joo is hiding a mole within the NIS, manipulating agents to locate hidden gold bars for her. Realizing the depth of corruption, Jeong Hae-seong erases all traces of their presence in her office, setting the stage for a larger battle ahead.
A School Party Unveils Dark Secrets and Betrayals
The school’s Byeongmun Night party becomes the backdrop for several explosive confrontations. Seo Myeong-joo gathers parents of elite students, promising them a future built on academic superiority, while behind the scenes, students struggle with friendships, betrayals, and buried secrets.
Lee Ye-na and Ahn Yu-jeong’s once-close friendship reaches a breaking point due to Lee Ye-na’s growing arrogance, which distances her from her peers. Meanwhile, Jeong Hae-seong’s realization about the mole shakes his confidence in the mission, leading to a moment of vulnerability. When Oh Su-ah takes him out for a drink, she urges him to find at least one person he can trust, assuring him that she is willing to be that person. Their conversation takes a shocking turn when Jeong Hae-seong reveals his true identity as Jeong Shi-hyeon, her childhood friend from elementary school.
Seo Myeong-joo’s Corruption is Exposed
Meanwhile, Lee Ye-na stumbles upon a conversation between Lee Seung-jae and his father, where they discuss tampering with student grades to secure spots in Seo Myeong-joo’s elite “Edu-City” project. When Lee Ye-na confronts him, he reveals the deep-rooted corruption behind the school’s academic system—Seo Myeong-joo has been manipulating grades for students with influential parents, in exchange for their financial support.
Oh Su-ah discovers a mysterious card belonging to Lee Seung-jae, which contains a secret link to documents detailing the grade manipulation scheme. Although she initially plans to return the card, curiosity gets the better of her, and she opens the link, exposing the full extent of the fraudulent system. She pleads with Jeong Hae-seong to help her gather evidence, but he hesitates, fearing that involvement in an unauthorized mission could lead to his expulsion.
Jeong Hae-seong Risks Everything to Protect Oh Su-ah
As tensions mount, Jeong Hae-seong sees his sister, Ahn Yu-jeong, working tirelessly to become an agent like him. Motivated by his duty to protect her, he finally decides to help Oh Su-ah find proof of the scandal. That night, he secretly places a tracker under a restaurant table where Seo Myeong-joo, Lee Seung-jae, and his father meet to discuss their plans. Through this, he learns that Seo Myeong-joo has discovered Oh Su-ah’s investigation and plans to eliminate her.
Realizing the imminent danger, Jeong Hae-seong rushes to the school, where Oh Su-ah is digging through old documents. He convinces her to leave with him immediately for her safety. Meanwhile, his superior, Ahn Seok-ho, is furious at his divided attention, demanding that he focus solely on his official mission. Their confrontation escalates, leading to a direct order from Ahn Seok-ho to abandon everything else.
An Intruder Strikes: Oh Su-ah’s Life is in Danger
As Jeong Hae-seong grapples with his next move, Seo Myeong-joo intensifies her plans. She instructs the mole to eliminate Jeong Hae-seong, suspecting that he knows too much about the hidden gym and its secrets. Meanwhile, Lee Ye-na, tormented by guilt, visits Ahn Yu-jeong’s house after arguing with Seo Myeong-joo about the grade scandal.
In the final moments of episode 8, Jeong Hae-seong returns home only to find Oh Su-ah lying unconscious on the floor, a sign that someone had broken in while they were working together. With the stakes now higher than ever, the fight for the truth is no longer just about exposing corruption—it’s about survival.
Final Thoughts: The Battle for the Truth Has Just Begun
Episodes 7 and 8 of Undercover High School take the drama to a new level, blending espionage, academic corruption, and deep personal stakes. As Jeong Hae-seong and Oh Su-ah get closer to the truth, they find themselves entangled in a dangerous game where trust is scarce, and betrayal lurks in every corner. With Oh Su-ah’s life in danger and Jeong Hae-seong now a target, the next episodes promise even more shocking revelations and high-stakes action. Will they be able to expose Seo Myeong-joo before it’s too late?
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FAQs
1. Where can I watch Undercover High School episodes 7 & 8?
Undercover High School airs every Friday and Saturday at 9:50 pm KST on MBC. International viewers can stream the episodes on Viki, Kocowa, and Rakuten V.
2. What did Jeong Hae-seong discover about Seo Myeong-joo?
Jeong Hae-seong found out that Seo Myeong-joo has a mole inside the NIS, manipulating agents to find hidden gold bars. She is also involved in tampering with student grades for personal gain.
3. What happened to Oh Su-ah at the end of episode 8?
Oh Su-ah was attacked by an intruder while investigating Seo Myeong-joo’s secrets. She was found unconscious by Jeong Hae-seong, leaving her fate uncertain.
