The story focuses on Im Yoona, the protagonist of the story of a girl on a wheelchair. 8 years ago, she got into an accident where her mental nerves are preventing her from standing up. She had not only lost her legs up until now, but also her memories, and her mother. And 3 years of her life. Her father passed away from an illness the same year she woke up, leaving her brother and herself in the care of their stepmother and stepsister.

Now that she is old enough, she dreams to pursue a career in Criminal Psychology, working as a detective, but in order to do that, she needs to heal from her wounds and walk again.

Lee Gikwang is the leader of the Severe Crime Unit, youngest detective to achieve this role, most competent and has quite the reputation. The family backgroung, the skills, the face. He is faced with a 8 years old case that brought him to Yoona who might be able to help him to finally close this case.

Never did they expect to have people around them to betray them.