In 1983, a pick pocket attacks higher school educator Ji-hwan. In 2015, homicide detective Gun-woo is taken during a pursuit and loses consciousness. Both men are accepted to the same hospital in different schedules, and both their hearts stopped and start again in exactly the same moment. A force binds them together, allowing them to see through one another's lives. So on realizing they come in fatal threat and that the women resembles eachother, both men must team up to track the past and change her destiny.