Undercover High School- Episodes 7-8
Childhood Connections, Hidden Files, and a High-Stakes Piano Duet
Episode 7 of Undercover High School hits all the right notes—literally and emotionally. With a deepening conspiracy, a covert piano mission, and romantic sparks flying left and right, this episode brings us thrilling action, heartfelt flashbacks, and long-buried secrets. Let’s break it down!
The Past Comes Calling
The episode opens with Hae-seong and Soo-a leaving her mother’s diner. When her mom calls her by her childhood name—Bong-ja—Hae-seong instantly realizes who she is. But Soo-a misinterprets his smile as mockery and storms off. At home, Hae-seong finds an old photo of them as kids, triggering a flashback to when little Soo-a adorably proposed to him.
Meanwhile, Ye-na finds herself in hot water with Myeong-ju again after her mother discovers signs of self-harm. In a twisted moment, Myeong-ju cuts her own arm, coldly telling Ye-na that emotions don’t matter—they must be perfect to represent the school.
Dancing Teachers and Friendly Praise
The next morning, Hae-seong catches Soo-a dancing while cleaning the staff room—an attempt to earn extra points toward becoming a full-time teacher. Embarrassed, she tries to explain, but Hae-seong praises her, leaving her flustered. Later, she wonders if his words mean he likes her. Ri-an quickly dashes her hopes: he’s probably just being nice.
The teachers are tasked with choosing the new “face of Byeongmun High.” When the vice principal leans toward another male student, Soo-a steps up and fights for a fair vote. In the chaos, she accidentally checks the wrong name—but Hae-seong still wins!
Apologies and Honest Conversations
While celebrating, Hae-seong crosses paths with Yoo-jung. He apologizes for interfering in her life, and she opens up a little—revealing that Ye-na isn’t all bad, just complicated. But just as they reconnect, Hae-seong is pulled away by his team.
The NIS team has big news: the detective investigating Kim Hyeon-ho’s death covered it up as a suicide. Why? His sick daughter was suddenly transferred to a luxury hospital owned by the Byeongmun Foundation. The corruption runs deep.
Mission: Piano Duet
For the next clue, Hae-seong needs to play a duet on the piano in Myeong-ju’s office. Mi-jung points out it requires two people—and who better than Soo-a to teach him the piece? Though Hae-seong protests, Seok-ho makes Soo-a an honorary field agent, in exchange for supporting her path to full-time employment.
Hae-seong is annoyed, but he eventually asks Soo-a why this means so much to her. She admits she’s doing it for one of her former students. That softens him, and they begin preparing together.
They hatch a plan to get Principal Park’s fingerprint to access the office. Soo-a checks out a book Park had reserved, and Hae-seong lifts a clean fingerprint from the cover. Later, during piano practice, he’s clearly more distracted by Soo-a than the notes. They even sneak in a self-defense lesson, getting a little too close for comfort.
Undercover at the Gala
Seok-ho takes Soo-a to the NIS headquarters and makes it official—she’s now part of the mission. The team plans their infiltration during the Night for Byeongmunites, when Myeong-ju will be busy with parents.
On the night of the event, Young-hoon enters as a waiter, while Hae-seong and Soo-a arrive together, turning heads. Hae-seong is stunned by Soo-a’s dress, and a flashback reminds us of the time little Soo-a told him he could propose when she was all dressed up.
Before the mission begins, Hae-seong gives her an injection in case of emergency and a camera necklace, promising to protect her.
Meanwhile, Yoo-jung discovers Ye-na has hurt herself again. When she tries to help, Ye-na lashes out, calling her a servant. But this time, Yoo-jung stands up for herself. They exchange slaps, and the power dynamic finally shifts.
Breaking In and Playing the Clue
At the party, Myeong-ju shows off a rare liquor brewed by Chairman Seo Byeong-mun, offering it to parents as part of her grand vision for Edu-City. She even hands out black cards as tokens of access.
Outside, Young-hoon cuts the power, giving Hae-seong and Soo-a the window they need. But Principal Park quickly restores the electricity. Thinking fast, Young-hoon poses as a parent and causes a scene, distracting the guards. Mi-jung seals the moment with a kiss, keeping the team off the security cameras.
Hae-seong and Soo-a reach Myeong-ju’s office and play the duet flawlessly. But nothing happens—until Hae-seong notices one piano key isn’t working. Time’s up. Seok-ho tells them to retreat.
While deleting security footage, Hae-seong stumbles upon a shocking file titled: “Undercover High School.” Inside is everything—the mission details, and his own profile.
We flash back to Hae-seong’s first day at the NIS, where Seok-ho asks him to choose a name. A heartwarming memory shows little Si-hyun telling his dad he wants to be called Hae-seong, meaning “comet,” because he loves stars.
A Glimpse of Something More
The episode ends on a soft note. Back during one of their piano sessions, Soo-a watches Hae-seong intently and smiles—maybe for the mission, or maybe… something more.
Dangerous Discoveries, Secret Schemes, and a Break-In Gone Wrong
Episode 8 of Undercover High School continues the momentum with new clues, deep betrayals, and a shocking ending that leaves us breathless. As Hae-seong and Soo-a peel back the layers of corruption at Byeongmun High, a mysterious clue leads them closer to the truth—but danger is always one step behind. Let’s dive in!
Secrets Behind the “Do” Key
Fresh off the piano infiltration, Hae-seong stumbles across the Undercover High School operation file on Myeong-ju’s computer. He and Soo-a make a quiet escape, and back at home, the NIS team realizes the silent “Do” key on the piano must be part of the next clue. But something’s off with Hae-seong, and Seok-ho notices—though Hae-seong brushes it off.
While the team recovers, Soo-a helps clean up after the school event and witnesses Han Seung-jae rudely berate a server. Neither he nor his powerful father apologize. After they leave, the server quietly slips Soo-a a black card that Seung-jae dropped. Across town, Myeong-ju smirks at her piano—clearly satisfied the third clue has played out.
Clues and Confessions
Meanwhile, Young-hoon flirts with Mi-jung again—only to be shut down when she says she’s seeing someone. Elsewhere, Soo-a deciphers the school anthem using only the “Do” notes played by the ghost girl, uncovering a riddle: “When the one with the bead faces the sun, the gold will shine.”
She rushes to share the clue with Hae-seong at the grocery store, but he’s distant. Frustrated, she drags him out for a drink, where he finally reveals what he found in Myeong-ju’s office—and that he no longer trusts anyone in the NIS. Soo-a offers comfort and her support.
During their walk home, Hae-seong finally confesses: he’s Si-hyun, her childhood friend. The revelation stuns Soo-a. They reflect on the past, how he vanished after his father went missing, and why they changed their names.
The Black Card Conspiracy
The next day at school, Ri-an encourages Soo-a to check out the website on the black card. What she finds is disturbing: a pre-determined list of students’ grades. Meanwhile, Ye-na sees Seung-jae’s father give him another black card and watches him panic over the one he lost.
She confronts Seung-jae, asking how his father knew he'd win a contest that hasn’t even happened yet. He spills the ugly truth—Myeong-ju has been manipulating the rankings all along. She even let Ye-na top the class as part of her scheme.
Soo-a tries to dig deeper, but someone tips off Myeong-ju. The chairwoman corners her with a veiled threat about following the rules. Rattled, Soo-a runs to Hae-seong—but he’s overwhelmed and tells her to wait.
Later, when Hae-seong sees Yoo-jung studying hard and telling him she wants to be an NIS agent like him, something shifts. He decides to act.
Soo-a’s Determination
That night, Soo-a finds the black card’s website has been taken down. In a secret meeting at a restaurant, Myeong-ju deletes the URL and discusses the situation with Seung-jae and his father. Seung-jae casually mentions that Ye-na knows too, which alarms Myeong-ju.
Afterwards, in a chilling scene, Myeong-ju beats Seung-jae in the bathroom to silence him. Meanwhile, Hae-seong races to Soo-a, who is still investigating the grade scandal. She confesses she once failed to protect a student from being falsely accused and won’t let it happen again.
They bring all the evidence to Hae-seong’s place, connecting parents involved in the scandal to Myeong-ju’s Edu-City project. Hae-seong suspects the NIS mole must also be getting a cut.
Tension at Headquarters
At the NIS office, Hae-seong briefs Mi-jung and Young-hoon. When Seok-ho arrives, he warns Hae-seong to focus solely on finding the gold bars. Their argument catches Director Kim’s attention. When Hae-seong fills him in, Kim cryptically says he’ll think about it.
Soon after, Myeong-ju receives a call—someone has informed her about Hae-seong.
Mission Aborted? Not So Fast
Back in class, Hae-seong receives a devastating text: his mission has been terminated. Refusing to give up, he tells Soo-a he’s going to bait Myeong-ju by pretending he’s close to finding the gold. A golden opportunity arrives—Myeong-ju is having lunch at school.
Hae-seong casually sits next to her and drops a hint, asking if the gym has ever been renovated. Myeong-ju catches on immediately and brings up the fourth ghost story. Hae-seong wraps up quickly and leaves, knowing he’s gotten her attention.
Ye-na’s Breaking Point
That night, Ye-na confronts her mother. Myeong-ju admits to rigging grades and insults Yoo-jung. But Ye-na finally fights back, defending her friend.
A flashback shows how the two first became friends—Ye-na admired Yoo-jung’s natural talent and kindness. In the present, she shows up at Yoo-jung’s home for dinner and thanks her before heading off.
A Shocking Attack
Soo-a’s research leads her to suspect that Lee Jun-ho, her colleague, might be involved in the scandal. She heads to Hae-seong’s house with more materials, but finds the gate open. Inside, she sees a shadowy figure—and then everything goes black.
Hae-seong returns home and finds Soo-a unconscious on the floor.
The episode ends with a poignant flashback: young Soo-a promising her student Min-ji that she’ll become a full-time teacher one day.
DramaZen's Opinion
High Drama, Deep Secrets, and So Much Heart!
Episodes 7 and 8 of Undercover High School were an absolute rollercoaster—and I loved every second of it. Episode 7 gave us swoon-worthy moments (that piano duet!!), clever spy antics, and the long-awaited reveal that Hae-seong and Soo-a are childhood friends. The chemistry between them is electric, and their dynamic just keeps getting better.
Then Episode 8 cranked up the tension with the school’s rigged grade system, black cards, and Soo-a’s heroic stand for her students. Myeong-ju continues to be chillingly ruthless, and the deeper this Edu-City conspiracy goes, the more intense it gets. And that cliffhanger?! I gasped. Protect Soo-a at all costs!
The blend of undercover espionage, high school politics, and heartfelt backstories is so addictive. Can’t wait to see how Hae-seong fights back in Episode 9! 👊💥
