Lee Seunghyun had to make a 20-hour long journey from Canada to return to his hometown to witness the funeral of his only remaining family, his twin sister, Lee Seungnie, who died suspiciously.

His instincts as a detective made him draw that conclusion, ever since he saw the weirdness in Seungnie's corpse his suspicions grows, especially with the fact that his twins tried to contact him and ask for help just hours before her death.

Driven by the desire to unravel the mystery of Seungnie's death, he must face Kwon Jiyong, Seungnie's husband who is still grieving and does not believe that his wife's death is not an ordinary death.

Can they work together to solve the mystery of Seungnie's death? Where is Seunghyun so determined to reveal the mystery while he is getting carried away by the flow of erratic feelings because of his closeness to the widower that he cannot avoid?

Can Kwon Jiyong get rid of the growing feelings for Seunghyun without considering that man as a substitute for Seungnie, the wife he loves so much?