The past history of the iron bead Killer Shin Jae-ha has been revealed. Jung Sung-hyun's process of becoming Shin Jae-ha was portrayed in the 14th episode of tvN Saturday drama ⁇ Ilta Scandal ⁇ broadcast on February 26 (playwright Yang Hee-seung Yoon Eun-ho / directing Yoo Je-won). Ji Dong-hee was caught by her daughter Nam Hae-yi (played by Noh Yoon-seo) while trying to harm the southbound ferry with a metal bead, believing that Choi Hwang Chi-yeul (played by Jeong Kyung-ho) had changed because of the southbound ferry (played by Jeon Do-yeon). Ji Dong-hee kidnapped and confined Nam-hae to his rooftop room, and the escaped Namhae was hit by a car and was unable to regain consciousness. Choi Hwang Chi-yeul moved Namhae to a single room for the South Korean ship and tried to postpone the math camp, but Ji Dong-hee knew the lie that he had told him. "I do not think he's dead," he said, and Choi Hwang Chi-yeul said, "If you have such an idea, I will not be able to go with you anymore." Ji Dong-hee wrapped up his baggage and read sister Suhyun's diary. In Jeong Su-hyeon's diary, she said, "Shall I tell the only person I can trust, the only adult I have, Mr. Hwang Chi-yeul?" And Ji Dong-hee said, "I thought so, too. sister. So I wanted to protect you. Because we are the only adults we trust. "But Choi Hwang Chi-yeul abandoned me." And I forgot the sister. In the past, Jung Sung-hyun was a disciple of Choi Hwang Chi-yeul, and when his mother leaked the test paper, he revealed the truth and made an extreme choice. His brother Jung Sung-hyun witnessed it and met Choi Hwang Chi-yeul at the funeral hall. Jung Sung-hyun talked to Choi Hwang Chi-yeul a lot. Choi Hwang Chi-yeul said, "I gave you a sister, so it's sister." Jung Sung-hyun, who lost her sister Sung-hyun, suffered from her mother's abuse. "My mother sprinkled water on her son Jung Sung-hyun because she fell asleep while studying for the exam, and drove her to the cold veranda. Jung Sung-hyun fell down on the veranda, and when his mother woke up, he said, "Go in and study," and when he forced me to study, he looked bloody. Jung Sung-hyun implied that sister Jung Sung-hyun had killed her mother by falling from the veranda where she fell. Jung Sung-hyun was in court for murdering her mother but was found not guilty. Jung Sung-hyun, who became an adult afterwards, gave someone an envelope of money and bought Ji Dong-hee's identity and became an assistant to Choi Hwang Chi-yeul. Ji Dong-hee grabbed Choi Hwang Chi-yeul's hand and showed affection, and was thrilled with Choi Hwang Chi-yeul's memory of the pen that sister received from Choi Hwang Chi-yeul.