Rainbow Eyes

Detective Kyeong-yoon (Kim Kang-woo) and his long-time partner, Eun-ju, (Kim Min-sun) are working on a gruesome case. The victim, a young rich sports center owner, has been stabbed multiple times and although the crime scene has blood all over it, the killer has erased his tracks very carefully. The detectives find a strand of hair at the crime scene, which leads them to a swimming instructor as a major suspect in the case, until he gets brutally murdered in the same manner. This serial murder case hits a bottleneck until the detectives find out that the two victims were part of the same military unit and both were transferred to another base due to an unknown incident. However, there was another person involved in this twisted incident... is he the victim or the perpetrator?