Yun Ja-yu’s research partner, Kim Sin-gu, betrays her to settle an old score. In Blood Free, Kim Sang-ho plays Professor Kim Sin-gu.
Yun Ja-yu has worked with Professor Kim Sin-gu, a biotechnology scientist, for 20 years. Together, they developed artificially cultured meat.
Thanks to Professor Kim’s research, Ja-yu was able to establish BF and take her company to new heights.
However, years later, Professor Kim becomes a threat to BF and everything they have worked so hard to achieve.
Getting his revenge
As Professor Kim’s retirement day approaches, the BF lab faces a cyber attack from hackers claiming to be CitizenX, a notorious ransomware organization.
The hackers demand 80 billion won to unlock the lab’s computers and files; failure to pay them would prevent BF employees from accessing their files.
Eventually, after hiring Woo Chae-woon, Ja-yu agrees to pay the ransom on his advice, but not before her company’s reputation suffers damage.
The perpetrators behind the cyber attack also leak news that the culture liquid used by BF is full of germs.
Chae-woon figures out that CitizenX never attacked BF; it was an inside job. It is then revealed that the culprit is none other than Professor Kim.
Professor Kim wanted revenge on Ja-yu, blaming her for his wife’s death. His wife had cancer, and Professor Kim asked Ja-yu to test her technology on his wife.
Ja-yu was warned not to take advantage of Professor Kim’s desperation, but Ja-yu, eager to test her technology on a human subject, ignored all warnings.
As a result, Professor Kim’s wife, who might have lived longer without Ja-yu’s intervention, passed away, leading Professor Kim to blame Ja-yu for her death.
When it was time for Professor Kim to retire, he planned the ransomware incident to leave the company with the money he believed he deserved, even if it meant tarnishing the reputation of his life’s work.
Professor Kim’s death
The moment Ja-yu pays the ransom, Professor Kim celebrates, unaware that his colleague, Hong Sae-ip, has come to his house to drop off his belongings.
Hong Sae-ip overhears him celebrating and finds out that Professor Kim was behind the attack before anyone else.
This leads Professor Kim to attempt to kill her and make her death look like an accident. However, his attempts fail because Hong Sae-ip is rescued.
Professor Kim had planned to leave the country with the ransom money and relocate to the US to live with his son.
He assumed no one would doubt him if he were to go to his son, so he never bothered to get a fake passport. Now, because of Hong Sae-ip, his plans are ruined.
Professor Kim travels to Vietnam, then to Cambodia, where he gets a fake passport and plans to travel to Paris.
Chae-woon learns of Professor Kim’s plans, and the authorities are alerted. They wait for Professor Kim to arrive in Paris, but he never reaches Paris.
Professor Kim is poisoned on the plane, leading the public to accuse Ja-yu of killing the whistleblower who exposed the truth about the germ-filled culture liquid.