Choi Eun-sul (Kim So-hyun)'s parents become victims of a vicious murder case. Although Choi Eun-sul luckily escapes from the murderer's knife, she is hit by a car and loses her memory. Choi Moo-gak (Park Yoo-chun) is a small patrolman, and fate and coincidence closely link the two together. Oh Cho-rin (Shin Se-kyung) wakes up from a coma and is shocked to find that she has gained the special ability to see the smell of "injustice", which makes Oh Cho-rin very uneasy. In an accident, Oh Cho-rin knocks down Choi Moo-gak who is on a mission. Then, Choi Moo-gak, who is quick-eyed and quick-handed, saves Oh Cho-rin from the brink of death. With her special ability, Oh Cho-rin and Choi Moo-gak cooperate to successfully capture the robber that Choi Moo-gak wants to pursue, and the wheel of fate between her and Choi Moo-gak begins to spin. Her past, his past, two seemingly unrelated memories are inextricably linked.