Believer 2 introduces a new antagonist, Seob So-cheon, played by Han Hyo-joo. Seob So-cheon, also known as the Big Knife, is Mr. Lee’s most loyal subordinate.
In Believer 2, Jin Ha-rim’s stepsister, Seob So-cheon, comes to know that her stepbrother took raw materials used in Laika production to Korea. There, he signed a deal with Brian’s company.
He handed over the raw materials worth billions of won to Brian, who was supposed to make 5 kg of Laika for Mr. Lee’s organization. However, Jin Ha-rim lost his life, Brian was severely hurt, and the drug produced by Brian was confiscated by the police.
Mr. Lee’s organization needs to deliver the drug to one of their buyers, but they do not have enough raw materials. Due to this, So-cheon decides to go to Seoul to find the raw materials that her stepbrother lost.
So-cheon’s relationship with Mr. Lee
So-cheon considers Mr. Lee her father and lives to impress him. When Jin Ha-rim was alive, he and Jin Ha-rim were Mr. Lee’s most loyal subordinates. So-cheon hated her brother because she was jealous of him and feared losing her place to him.
In the past, despite her attempts to get him killed, Jin Ha-rim begged Mr. Lee to forgive So-cheon. Jin Ha-rim saved her life, not because he loved her but because he pitied her. There was no love left between them.
The two of them hunted down all the criminals who falsely claimed to be Mr. Lee and killed them. After Jin Ha-rim’s death, So-cheon was finally free of competition and became Mr. Lee’s most trusted subordinate.
However, that is when Mr. Lee decides to retire and live an ordinary life with his family in Norway. Mr. Lee hands the reins to So-cheon and allows her to run his drug empire in his name.
So-cheon refuses to accept the fact that Mr. Lee is not coming back. She keeps trying to impress him in the hope that he will return. She lives for his acceptance. All her actions are driven by her need to earn his approval.
So-cheon comes to Seoul and meets Brian, who tells her about Rak. As Rak wants to find Mr. Lee, he steals the raw materials from Brian’s factories, leaves a sample of his Laika with Bo-ryeong’s body, and lets So-cheon find him.
So-cheon gets Rak to produce Laika and keeps sending Mr. Lee reports on Rak’s work. Eventually, Mr. Lee calls her to tell her that she does not need to send him reports, as he will not be coming back.
This breaks So-cheon’s heart, and she starts fighting Rak when he asks her about Mr. Lee. She beats him black and blue and almost kills him. She stops only when he promises to speak to Mr. Lee and tell him that he is making Laika for him.
This gives So-cheon hope that Mr. Lee might return. Her brief moment of happiness gives Rak the opportunity to stab her. At the same time, Jo Won-ho arrives there and kills So-cheon to save Rak.
So-cheon dies serving Mr. Lee. Later, when Rak finds Mr. Lee and tells him about So-cheon’s death, Mr. Lee remains unmoved, as he never cared about So-cheon the way she cared about him.
Also Read: Believer 2 summary and ending explained