Ji O wakes up from losing his consciousness and has no clue where he is. In fact, he isn’t sure who he is either. He just knows that he has a body covered in wounds and there are fallen people all around him. One man walks up to him with a knife in his hands. A year goes by and Gu Reum, a police officer, finds out that the man she was searching for is dead.

Ji O returns to the lab where he lived as a child. An unexpected someone comes to meet Ji O and tells him a shocking truth. Meanwhile, Gu Reum finds a new lead on her search for her parents and continues her investigation. When she follows the lead, she winds up at a place she once visited before.