Forgotten is a mystery thriller by the South Korean director Jang Hang-jun from 2017. The main roles are Kang Ha-neul, Kim Mu-yeol, Moon Sung-keun and Na Young-hee. Netflix secured the rights to international distribution of the film.
Jin-seok moves into a new house with his brother and parents. He had always looked up to his older brother Yu-seok. He was always the best in his class, in sports and intellectually, exuding wit and charm. However, he was in a car accident, which left him limping on his left leg. When he arrives at the new house, he is told that a room is not yet available and should not be entered, as the previous tenant would still pick up things from there in the course of the month. Yu-seok has to sleep in the same room with Jin-seok.
However, he keeps hearing noises from the room. He also keeps having nightmares about ghosts and torture. One reason why he has to take pills. One evening he walks down the street with Yu-seok to relax. On a hill overlooking the city, Yu-seok receives a call from his father. This would need a document. Jin-seok should wait there, Yu-seok would bring it to his father quickly. But on his way, Yu-seok is kidnapped. Jin-seok barely realizes, but can't do anything.
The family does not receive a call from the kidnappers. The police do not know the identification number that Jin-seok remembers. After 19 days, Yu-seok returns but can't remember anything. Jin-seok notices that Yu-seok always leaves the house in the evening. He also saw him hobble on his right leg. He decides to follow him in a taxi and through dark alleys. Yu-seok meets the two who pretended to be police officers in the kidnapping case to Jin-seok. Yu-seok seems to be the boss of these. Jin-seok continues to follow Yu-seok, but is discovered by the two fake policemen. Persecution ensues in which Yu-seok can capture Jin-seok.
The next morning, Jin-seok wakes up and Yu-seok tries to convince him that he was only dreaming everything. Scared at first, Jin-seok believes him. Yu-seok asks him if he was taking his medication. However, he did not take it the day before. In the evening, however, he overhears his mother talking to someone on the phone, which sounds like a plan, and she talks about Jin-seok as a bastard. Jin-seok then escapes to the police and says three people are posing as his family. He also learns that he is not 21 at all, but already 41 and that it is not 1997, but 2017.
The police believe that Jin-seok is mentally confused. Jin-seok comes back to reality more and more and sees his aged, true self in the mirror. He decides to return to the new house to find out all about the background. Yu-seok tells him that Jin-seok murdered a mother and a daughter in this house 20 years ago. You would know exactly that it was him. The case caused a stir at the time, but could not be resolved until the statute of limitations. The family should then have hired a private detective. When he finally found Jin-seok, he remembered nothing. But the family wanted to know everything and could not take revenge if he did not remember.
Jin-seok was traumatized by his parents' death and murder in 1997, so Yu-seok tried several methods to restore Jin-seok's memory. This also included recreating the day the family moved with hypnosis and a few adjustments. But Jin-seok does not remember and is convinced that he is not a murderer. He tries to escape again, but is hit by a car and comes to the hospital. There he can suddenly remember. Due to the Asian crisis, he couldn't find a job, his brother was in hospital after the car accident and he needed money for the operation.
A doctor offers him money for a murder. Jin-seok is supposed to kill his wife, but not the two children. Jin-seok accepts, but wants to back down in the house. However, the daughter Chan-mi discovers him and begins to scream. Jin-seok wants her to stop. A scramble ensues in which he kills both his daughter and mother. The doctor was also hit by the financial crisis and has taken out insurance for his wife. In a tussle between Jin-seok and the doctor, the latter falls from the roof.
Jin-seok wakes up in the hospital and learns that the investigator was the surviving son. He wants to know the truth. After his parents died, his relatives took all the money and put him in an orphanage. He already had evidence from the insurance companies that his father may have commissioned the murder of his mother. To protect him, Jin-seok lies to him and says it was all his plan. The detective then commits suicide.
Kang Ha-neul as Jin-seok
Kim Mu-yeol as Yoo-seok
Moon Sung-keun as father
Well Young-hee as mother
Choi Go as Choi Seung-uk