★Both simplified and tradtional Chinese translation rights sold.
★Film adaption rights sold.
★"Because when people are cornered, they become beasts". A stunning debut of a Korean suspense novel! A heart-pounding mystery thriller that is highly anticipated in the film industry!
★Six women at their wits' end and the death of a man. The author's breathtaking writing keeps readers spellbound until the very last moment!

There is no good person and no bad person.
There are six women living in women-only studio apartment and the story begins with one dead man’s body found in the same floor. They become suspicious of each other on who killed the man. Each character is talking their own personal story as a separated narrator and all seems to have both good and evil aspects so readers cannot predict the conclusion to the end. The author is trying to find horror brought from our daily lives.

Author: Casey
He is normal office worker. He has suffered mild dyslexia and cannot even finish a few pages of book. This is why he decided to write his own fiction book. Casey is his writing name and Four Knock is his debut title.

Room 301
"In nature, there are predators and prey."
As a shaman, she has set up a small shrine near her studio apartment and offers fortune-telling services. She empathizes with the exhausted and struggling young people, providing them with affordable psychological counseling. She also shows great concern for the different situations of the women on the same floor.

Room 302
"I live like a ghost, silently and diligently."
She is a freelance designer who works from home and has lived in the studio apartment for nearly two years. She is sensitive to noise, but she carefully listens to the sounds from her neighbor in Room 303 to infer their private life.

Room 303
"When people are cornered, they become beasts."
She is a social worker who takes care of a person with intellectual disabilities in Room 304. When her once kind and reliable boyfriend, like a big dog, changed dramatically after a business failure, she tried hard to find a safe way to break up with him.

Room 304
"The sister next door is a good person."
She is a person with intellectual disabilities living alone. She calls the woman in Room 303 "sister" and enjoys keeping fish, with several aquariums in her home.

Room 305
"It's better to be afraid than to hate."
A woman who sells handmade accessories at a street stall. People are afraid of her and avoid her because of her piercings and tattoos. She is especially harassed by the person in Room 306. "At my age, living alone, do I really need to hear such words?"

Room 306
A woman in her fifties is responsible for cleaning and managing a building of studio apartments. She spreads rumors about the residents of the building. She is the first one to discover the dead body and report it.