During the summer in the present day, Jeon Yeong Ha runs a vacation cottage located deep in the woods. His peaceful life is shaken by the sudden appearance of a mysterious woman named Yoo Seong A. In the early 2000's, Koo Sang Jun ran the same vocation cottage as Jeon Yeong Ha did years later. Koo Sang Jun and his family also lived there, but, during the summer, something happened at his vacation cottage and Koo Sang Jun lost everything because of that. At that time, Yun Bo Min worked as a police officer at the nearest police substation from the vacation cottage. 20 years later, Yun Bo Min is transferred to the same police substation where she worked before and she begins to work there as the chief. She enjoys solving things and begins to observe Jeon Yeong Ha closely. (Source: AsianWiki)