After her father's death, Ha So-min receives a call in her mother Kim Mi-yang's voice. However, So-min soon realizes that the one behind the phone is Ma Seok-gu using voice technology. Searching for clues, she finds an SOS from Mi-yang and chases a mysterious woman. As secrets unravel, So-min learns that Mi-yang's voice is being exploited by a phishing ring. Consumed by grief and rage, she vows revenge, joining forces with Detective Park Jeong-hun and turning to deepfake herself for a strike.

When So-min learns that the Ilseongpa is planning to send the Yongsinje event staff to a Chinese call center, she seizes the opportunity to disguise herself and sneak into the Ilseongpa captain's house. Sensing that Jeong-hun will return to his police officer role and intervene, she confesses her lies to President Kim and makes a new proposal.

Unlike the call center, Somin, known as the luxurious Ilseongpa stronghold, catches Seokgu's eye thanks to her overwhelming skills. Seokgu senses a familiarity yet a strangeness in her, and becomes suspicious of her identity. However, Somin exposes the Heungsam-i faction's spy, averting the crisis and earning Seokgu's trust.