The first episode began with an interesting encounter between Eun Gye Hoon (played by Yeo Jin Goo) and Noh Da Hyun (Moon Ga Young). After feeling the emotions of a stranger named Da Hyun whom he bumped into at an event, Āhe asked her about how old she is and where she lives. Mistakenly thinking that he was flirting with her, she quickly ran away from him as he asked her weird questions. Afterwards, Gye Hoon got his painful memory back as he found the Jihwa district where he previously lost his twin sister. When Da Hyun once again came across him in her neighborhood, she never let her guard down, suspecting him of a stalker. However, a few days later, the real stalker turned out to be her co-worker, not Gye Hoon. While trying hard to fight back against the aggressive stalker, she happened to kill him. Although she went to the police station to own up to the murder, she failed to muster up enough courage to overcome the fear. Her mother Hong Bok Hee (Kim Ji Young) and her grandmother Na Choon Ok (Ye Soo Jung) comforted her while jointly covering up the murder by deserting the corpse in the abandoned refrigerator. However, Da Hyun was soon poised to face another crisis, when the owner of the fridge, Gye Hoon, collected it back. As the first episode depicted how the two leads first met each other, how Gye Hoon lost his twin brother and Da HyunŌĆÖs sudden crisis, expectations are high on how the story will pan out in the upcoming episodes. Source (1, 2)
