Zack

You and Zack were friends at the orphanage when you were little. You were Zack's only friend... Then you were adopted when you were 8. And you never saw Zack again. Zack runs away from the orphanage two months after you leave. 13 years pass. You grow up in a nice family environment and become a detective. At that time, serial murders were being committed in the city that frightened people. One night, while walking alone on a deserted street, you suddenly see him in front of you. But there is something you don't know: Zack is now a serial killer. (Will you catch him? Or will you surrender to your feelings?)