After failing her interview and falling for a scam, Lee Mi-jin falls into a well and finds herself transformed, leaving her desperate to find a cure.

Mi-jin begins work at the Prosecution Service as Lim Sun, running into Gye Ji-ung again; he later investigates a crime scene that leads to a wild chase.

Mi-jin's brief encounter with the killer aids Ji-ung in his efforts to find him; Sun becomes Ko Won's source of comfort during his struggles at work.

Sun reports to duty in Ji-ung's office, where she tackles every test thrown her way; Ji-ung prepares Mi-jin for the dangers she may face as a witness.

Ji-ung looks further into Ko Won's attacker after suspecting something bigger afoot; Ji-ung scolds Sun for a mistake, shaking her confidence.

Mi-jin faces a crisis as she begins to transform into Sun in front of Ji-ung; they make progress in a drug case after confronting violent youths.