Ep 12. Episode 12

Sun-Ok is still trying to hunt down the mermaid, but she soon becomes frustrated when she sees that not only is Joon-Jae protecting her, but that she's in love with him. As Sun-Ok continues to try and capture the mermaid, Joon-Jae and the mermaid try to figure out how they can stay together without endangering her life. Meanwhile, Joon-Jae's friend, who is a genius hacker, is approached by his old boss who wants him to help with a new job. But the job is not exactly what it seems, and Joon-Jae and his friend soon find themselves in over their heads. The episode also explores the backstory of the mermaid and her relationship with her human father, as well as Joon-Jae's relationship with his own father. As tensions rise and danger lurks around every corner, Joon-Jae and the mermaid must use their wits and their love for each other to stay alive.