In 1999, an accident happened, in which a professor of a famous college was found dead in his office. In 2019, a young golf instructor was found dead in the bathtub at his home. However, surprisingly, 4 suspects in the murder case 20 years ago are now the prime suspects in a similar murder case. Who committed the murder and for what purpose? Could it have been Gung-cheol who became furious after he received his wife’s naked photo? Could it have been Jae-hun who was trying to protect his friend’s wife? Could it have been Hyung-woo who was caught having an affair with a young woman? Or could it have been Chun-bok who out his female friend’s relationships? As the mystery of an unsolved murder case unravels, the secrets and lies holding them together breaks them apart.