<Korean TV Series NOW> ”Undercover High School” EP7, Seo Kang Joon's team collaborates with Jin Ki Joo = Viewership rating 6.8%, Synopsis/Spoiler

※This article contains spoilers. In EP7 of the MBCTV series "Undercover High School" (viewership rating: 6.8%), Hye-sung begins to track down the truth behind the third ghost story.
The story depicts the struggles of Seo Kang Joon and Soo Ah (Jin Ki Joo). Hye Sung couldn't help but smile when she found out that Soo Ah was her first love, Oh Bong Ja. Hye Sung and Bong Ja when they were young
Sua recalls memories of her past and mentions an episode with Hye-sung to a fellow teacher, pretending to be talking about a friend, igniting romance between the two.
Meanwhile, agents from the National Intelligence Service's Domestic Team 4 were investigating the third ghost story when they heard the school song that Hye-sung had recorded on the wall clock.
It turns out that it was an ensemble of Oh Hans. In order to get a clue to the ghost story, the two must play the school song together. While searching for the performers, Sua joins them.
This led to her close collaboration with the four domestic teams. In particular, Hye-sung and Su-a demonstrated perfect teamwork and provided the necessary power to unlock the security system in the Chairman's Office.
The fingerprints of Principal Koo (Park Jin Woo) have been obtained. The day of the long-awaited event "Night of the Byeongmuns" has arrived. Young Hoon (Jo Bok Rae) has entered the building under false pretenses and is taken into custody by Myeong Joo (Kim Shin Rock).
While the others were gathered, he went to the power distribution room and cut off the power to the electric motor. During the blackout, Hye-sung and Su-a tried to move to the chairman's office, but the power was restored sooner than expected, putting the operation in danger of failing.
In order to resolve this, Mijung (Yoon GaYi) and Younghoon boldly kissed each other to catch the attention of the security guards.
Thanks to Mijeong and Younghoon buying time, Hye-sung and Su
A arrived safely in front of the president's office. However, security personnel appeared and a scuffle ensued. The two, who had even undergone physical training, combined their strength to subdue the security personnel and enter the president's office.
entered.