When Sang Hun heard the woman screaming in his apartment, he looked outside his apartment and saw Tai beating a woman with a hammer. Sang Hoon sees the man named Tai through direct contact with the eye. The next day, that woman was found dead in her place, where investigator Jay Yub begins his investigation into that obvious case. Sang Hoon is still horrified and does not tell the investigator Jay Yup what he saw because he is trying to protect himself and his family from the killer who threatens his life.