35-year-old Jang Young-sil (Kang Ye-won) has never held a full-time job her entire life, despite having countless qualifications. After being fired from her contract job at the National Security Agency, she accidentally discovers her ex boss's (Jo Jae-yun) secret… Desperate for a job, Young-sil offers to go undercover at the phishing centre, and strikes a deal with her ex-boss. If she successfully retrieves the money without alerting the authorities, she will be given a permanent position at the agency. While undercover at the phishing centre, she meets foul mouthed cop Na Jung-an (Han Chae-a) from the Intellectual Crimes Unit, who was assigned to infiltrate the organisation to uncover the identity of the mastermind behind its operations. What will be the final outcome of their undercover mission?