Seo Jin discovers that his alter ego Robin has made an appearance for the first time in five years. Ha Na is the sole witness in finding the man behind Doctor Kang's disappearance.
Seo Jin is extra stressed when faced with Lee Soo Hyun and the incident from his past, but while the case seems to be wrapping up-- it may only just be the beginning.
As the real villain hides in plain sight, Ha Na and Seo Jin are pushing themselves to find the truth-- but when the possibility of Doctor Kang being the culprit instead of the victim arises, it takes a mental toll on Seo Jin.
Ha Na finally learns the secret about Seo Jin and Robin, but one of them wasn't ready for her to know. Seo Jin enters the belly of the beast when he goes to Doctor Yoon for help.
Seo Jin has accepted Robin as a part of himself, but Robin struggles with his own identity. The incident from five years ago is revealed with a surprising twist to Seo Jin's illness.
Ha Na wants to help both Seo Jin and Robin, but Robin refuses to share her with another man. Seo Jin and Robin both formulate a plan to catch the real Lee Soo Hyun.