Episode 3 Summary: “Episode #1.3”
In this episode, Ha Woo-shin intensifies his efforts to uncover the truth behind his father's murder. He confronts Eun Hye-soo, attempting to coerce her into revealing more information by reminding her of a letter she once sent him. However, Hye-soo refuses to be manipulated and destroys the letter, signaling her unwillingness to cooperate under duress.

Meanwhile, Woo-shin devises a plan to extend his stay at the Haesong mansion. He learns from his assistant, Dong-rim, who has been observing secret sign language communications between Chairman Kwon and Secretary Yoon, that Haesong is involved in a clandestine operation to supply arms in support of a presidential candidate, Hwang Byung-cheol. Woo-shin uses this information to confront Chairman Kwon, who, realizing the potential threat to his plans, decides to keep Woo-shin and Dong-rim at the mansion until the elections are over . 

On another front, Woo-shin seeks the assistance of Choi Tae-sung, the mansion's chief of security. Initially, Tae-sung is hostile, even threatening Woo-shin's life. However, Woo-shin cleverly feigns poisoning himself and reveals he had taken an antidote, demonstrating his resourcefulness and causing Tae-sung to reconsider. Eventually, Tae-sung agrees to collaborate with Woo-shin, revealing that he has been undercover for two years, aiming to infiltrate Haesong's secretive "Team A" .

Simultaneously, Song Soo-hyun, Woo-shin's twin brother and a prosecutor, continues his investigation into their father's case. He receives a sketch from journalist Seo Hee, who claims to have witnessed the real murderer. Soo-hyun confronts Lee Chang-woo, the man convicted of their father's murder, but Chang-woo denies recognizing the person in the sketch, leading Soo-hyun to suspect a larger conspiracy . 

The episode concludes with Woo-shin and Tae-sung planning to exploit the mansion's fire suppression system, which uses halogen gas instead of water, to create a diversion. Their goal is to access the chairman's study during the evacuation, hoping to find evidence related to the Adamas and the murder .