![Psychopath Diary](https://image.chilimovie.com/public/300px/20200109/hGmNWy80ILs8wLTDLjnwtOieNw4.jpg)
It's the final battle between Dong Sik and In Woo. With the police heading their way, Dong Sik fights off In Woo, who has a gun pointed at Bo Kyung's face. As the police arrive, gunshots echo down the emergency stairway. Who will be the victor? In Woo, the psychopath serial killer? Or Dong Sik, the pushover?
Dong Sik's memory returns to him with Bo Kyung's help. When he realizes In Wook is the serial killer playing him as the fool, rage takes over him. Finally, Bo Kyung and Chil Sung help Dong Sik start to make his move to turn the tables on In Wook.
In Woo has Dong Sik right where he wants him. Dong Sik has no clue that In Woo is the one behind the blackmail and prepares for murder. Meanwhile, Bo Kyung, who thinks former police officer Park Moo Suk is the informant, finds his body.
Bo Kyung and In Woo both chase after Dong Sik for different reasons. And soon, both get closer to what they are after. Bo Kyung gets an unexpected hint from Dong Sik about the serial murders and starts to investigate a missing person case. Meanwhile, In Woo starts to become more active.
Dong Sik determines to kill Seo Ji Hoon and secretly plans how he's going to do it. In Woo tells Dong Sik about a company going public and urges him to buy as many shares as he can. Meanwhile, Ji Hoon and Chan Suk resort to the old-fashioned way to get rid of Dong Sik, and Bo Kyung goes on a suspicious call.
The story of a man named Yook Dong-sik who coincidentally witnesses a murder and picks up the killer's diary. While fleeing the scene, he gets into a car accident causes him to lose his memory. Due to the diary in his possession, he mistakenly believes that he is a psychopathic serial killer.