After getting alarming news from his fiancee, Cha Min has a mishap and receives an object called Abyss; Go Se-yeon meets someone who says that he is a friend.

Min explains what he did to Se-yeon, who is in disbelief over her circumstances; vowing to find her killer, she comes up with a way to help Min and herself.

Se-yeon and Min are stunned by what Park Gi-man has been doing, and they unwittingly get help from a police detective who thinks that she is someone else.

Convinced that he has seen his ex-fiancee, Min is frantic to talk to her, but Se-yeon tries to remind him that he is not the same person anymore.

After making a horrific discovery, Se-yeon considers using Abyss and tries to persuade Park Dong-cheol to keep investigating the murder of the prosecutor.

Park Dong-cheol tries to hunt down Oh Yeong-cheol, who keeps eluding the police; Min's mother doesn't know what to make of the changes she sees in her son.

Se-yeon finds herself viewing Min in a different light after realizing he has always been by her side; Jang Hui-jin reveals something surprising to Min.

Park Dong-cheol demands to know why Se-yeon interferes with the case; someone claiming to be Lee Mi-do appears out of nowhere.