The identity of the assailant who secretly entered Seo Kang-jun's house and stabbed Jin Ki-joo has been revealed.

On the 21st, the MBC weekend drama 'Undercover High School' depicted Oh Soo-ah (played by Jin Ki-joo) collapsing after being stabbed.

That day, Oh Soo-ah discovered signs of an intruder at Jeong Hae-seong's (played by Seo Kang-jun) house and confronted the assailant. Oh Soo-ah asked, 'Who are you? What are you doing here?' and as she took out her phone, the assailant brandished a knife to threaten her, prompting her to seize the opportunity to escape.

After a struggle, Oh Soo-ah, who had been stabbed, collapsed bleeding. Meanwhile, Jeong Hae-seong arrived home, found Oh Soo-ah, and hurriedly transported her to the hospital, saying, 'Soo-ah, stay with me. Soo-ah.'

Jeong Hae-seong treated Ahn Seok-ho (played by Jeon Bae-soo) coldly when he visited the hospital. Sensing this, Ahn Seok-ho approached, saying, 'Are you okay? We'll be here, so you should rest at home,' but Jeong Hae-seong retorted, 'It's fine, so just go away.'

Jeong Hae-seong started to speak, saying, 'It's not the Head of Team. Please don’t mind me and go inside,' but then stepped away. Later, he apologized to Oh Soo-ah, who was lying in a hospital bed, saying, 'I'm sorry. I'm sorry I couldn't protect you.' At that moment, Oh Soo-ah opened her eyes and smiled, saying, 'If you're really sorry, treat me well.' Jeong Hae-seong replied with a relieved smile, 'Are you okay? I was worried. Thank goodness.'

Oh Soo-ah revealed to Jeong Hae-seong that the instigator of the school grade corruption was Lee Jun-ho (played by Noh Jong-hyun). At that moment, Jeong Hae-seong, who received a phone call, realized that the person in his house was Lee Jun-ho.

[Photo] Capture from the broadcast of 'Undercover High School'

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