1983: Ji Hwan, a high school music teacher, is soon to wed his colleague and girlfriend, Yoon Jeong. Yoon Jeong becomes involved in a case and Ji Hwan attempts to protect her. Moments later, he is fighting for his life after he is stabbed by a mugger.
2015: Police detective Geon Woo is shot by a suspect. The two men who live 30 years apart, fight for their lives on the same
