Plot

When a bright high school student with memory loss enters a national talent show to help her struggling family, she finds her ordinary life flipped upside down by the sudden arrival of mysterious strangers seemingly connected to her past.

The movie begins with several images from across the world, showing kids being used as experimental subjects in the past. In the present, Dr. Baek visits a laboratory where a massacre has just happened. The corpse is still moving, and she orders her men to aim at the head. Two kids successfully escape from the facility and are being chased by Dr. Baek's men; one of them is Mr. Choi. He manages to capture one of the escaped kids, but the other one, who is a girl, is still missing. Because they lost her, Dr. Baek orders Mr. Choi to report the girl to HQ as decommissioned, since she will eventually die on the run.

In a small village near the laboratory, a farmer spots the girl unconscious and immediately takes her to his house. The doctor says that she will recover; however, he is afraid that the girl will lose her memories, including her name and age. Since the wife is having a hard time getting pregnant, they decide to adopt her. Ten years later, the girl, named Ja-yoon, is living a normal life as the farmer's daughter, without remembering her past. She wants to buy cow food but does not bring any money. The seller is unwilling to give it to her because she has not paid the previous debt. However, the seller's son, who has a crush on her, secretly loads the requested cow food into the truck, and she eventually drives away, which makes the seller furious.

It is revealed that Ja-yoon's mom is suffering from Alzheimer's disease, and her family is facing a financial problem. The father plans to sell a few more cattle, even though the price of cattle continues to free fall. After having a bath, Ja-yoon suddenly suffers a severe headache. Luckily, it doesn't last long. Later that night, she goes through the internet to find out information about Alzheimer's disease and discovers several doctors specializing in brain diseases, hoping that she will find a way to cure her mother.

The next day, Ja-yoon goes to school with her best friend, Myung-hee, who suddenly suggests that Ja-yoon join an audition for a national singing contest with a total prize of $500,000. She agrees because if she wins, she will be able to pay her mom's hospital bill, and money will not be a problem again in her family. Despite having no ability to sing, she eventually passes the preliminary stage as the candidate with the highest score. At home, her parents are very proud of her, but they are worried when Ja-yoon is told to perform her secret talent in the audition. Myung-hee assures the parents that nothing bad will happen. On the contrary, she will even get extra exposure because of that.

Not long after, they receive a mysterious call, which makes the parents more worried. Before sleeping, Ja-yoon tells her scared mother that everything will be okay and that she is not going to leave them. Later that night, while Myung-hee is having a sleepover, the severe headache occurs again; this time, the pain is much longer than before. On the other side, Mr. Choi is secretly watching her from a distance since Ja-yoon's identity has been exposed in the audition. The next day, they take a train to Seoul to join the next phase of the audition. On their way, Myung-hee offers to be her manager if she becomes famous, suggesting a 50-50 profit sharing.

Suddenly, a young man sitting in front of them intervenes. He claims that he knows Ja-yoon, but she doesn't seem to remember him at all. He is surprised when he discovers that Ja-yoon has a name. He states they used to be called by numbers and calls her "Ms. Witch," which makes the girl more confused. She still doesn't remember, and the young man attempts to slap her in the face, which shocks Ja-yoon. Myung-hee screams but is ignored by other passengers. He goes away and says that they will meet again. As he walks away, he collides with someone and insults him. Unhappy, the other guy tries to attack him, but he is just way too strong for him. The young man eliminates him and then throws the corpse off the train.

They arrive at the studio, and Ja-yoon's outstanding performance eventually allows her to advance to the quarterfinals, receiving overwhelming votes from the jury. They are very happy with the result, but as soon as they get out, Ja-yoon suffers the headache again. This time, it even causes a nosebleed, indicating that the disease is getting worse. It turns out that she once visited a doctor who said that the headache will take her life within two to three months, and a bone marrow transplant from her biological parents is the only way to save her. Meanwhile, Dr. Baek, who watches the performance on television, is very happy because her best creation is still alive and has finally been found.

Outside the studio, the girls are suddenly confronted by Dr. Baek's men, who attempt to kidnap them, but in a nice and polite way. However, a group of children coming out from the building distracts them, and they use the opportunity to call a taxi and get away from there, then taking a train to return home. Upon arrival, while Myung-hee is calling her dad for a ride, suddenly the young man shows up and threatens her, saying that he is going to kill her parents. Ja-yoon immediately runs towards her house while telling her best friend to call for assistance. It turns out that Myung-hee's dad, Mr. Do, is a police officer, and he decides to stop by Ja-yoon's house. When the young man is about to attack the house, Officer Do arrives and politely asks for their ID.

Not long after, the girls arrive home and cannot find anybody inside the police car, which makes them worried. Ja-yoon uses her power to locate the old men. They run in panic to the house, discovering that their fathers are playing chess together. Before departing, Officer Do tells Ja-yoon that the young man and his friends are Americans, but she claims that she doesn't know them. On the other side, the young man and his men confront a professor in his laboratory.

Turns out that he was a co-worker of Dr. Baek, and he refused to cooperate when he was asked; so they were sent by her to kill him. Outside the facility, the young man shows off his skill that allows him to control a human's mind and use a gun without touching it. After that, they burn the laboratory and leave.

The next day, Dr. Baek meets up with Mr. Choi. She suggests he take a vacation to Europe and orders him not to interfere with her business again. He is unhappy with the decision, but he has to comply with his superior. He warns her that Ja-yoon is a monster and must be killed, but Dr. Baek is not willing to do so. A few moments later, Mr. Choi secretly meets up with a professor who can help him cure his disease, but Mr. Choi has to kill Ja-yoon and bring him her head.

While having dinner, the other family members are worried about Ja-yoon's mom's condition, as her dementia is getting worse. She can't even recognize her daughter anymore. That night, Ja-yoon awakens from her sleep, crying in agony as the severe headache occurs again. Meanwhile, Dr. Baek's men sneak into the house and threaten Ja-yoon's mom with a gun. Realizing that, she immediately gets up. As soon as she leaves her bedroom, she learns that she has been surrounded while Myung-hee is taken as a hostage. A man shows up, claiming that Ja-yoon almost killed him in the past, but she insists that she doesn't remember anything and doesn't know him. She keeps begging until one of the men hurts her best friend. She is enraged and unleashes her real talents. She becomes very fast- as fast as light- and starts eliminating all of Dr. Baek's men one by one, ruthlessly.

After she eliminates the last man, the young man shows up and is amazed by Ja-yoon's real ability. The young man explains that Ja-yoon was built differently; she manages to excel in every subject without having to give extra effort. However, she still doesn't remember who the man is. He then shows her the scar on his forehead, telling her that she did that to him. The girl slowly remembers her past but still doesn't want to admit that she knows him. The young man urges her to follow him, or he will kill all the people in the village. She reluctantly agrees and tells her friend to take care of her parents.

On the other hand, Mr. Choi gathers all the field agents and is ready to assassinate the girl. On their way, it is revealed that Ja-yoon deliberately chose her foster parents, whom she was certain would never leave her. It was already well planned. Long story short, they arrive at an abandoned laboratory where Dr. Baek has been waiting, and she is directly brought to an interrogation room. She is tied up to a chair, and Dr. Baek welcomes her from the other side of the room. She feels so relieved after knowing that Ja-yoon is still alive. However, Ja-yoon still has no idea what's happening.

To make her remember all the past, Dr. Baek orders her man to inject a liquid into her. It is revealed that she was one of the experimental subjects, where Dr. Baek was in charge of that brain experiment. The professor claims that she is the best brain specialist in the world right now, and Ja-yoon was one of her best-engineered products. To make her even stronger, Ja-yoon was specially trained by her to be a cold-blooded killing machine. In the beginning of the movie, they tried to kill all the kids because their generation was a big success. They were able to control things and had very high intelligence. The higher-ups were afraid of the creation because they were worried that they couldn't control them, so Dr. Baek was ordered to decommission all of them. However, Ja-yoon was special at that time, and all of her men were unable to kill her.

Since the headache will eventually kill her if untreated in the right way, and her condition is getting worse, the professor orders the man to inject another serum into her, allowing her to unleash her full strength for only a month. She will need another injection in the following month, or the pain will become more severe. However, after receiving the shot, Ja-yoon's expression drastically changes. It turns out that she has never lost her memories and has been playing dumb all this time in order to reach the professor. It is also revealed that Ja-yoon purposely showed her talent in the audition to draw the professor's attention. She immediately breaks free and eliminates the man in the interrogation room.

Dr. Baek attempts to release the nerve gas to paralyze her, but she escapes through the ceiling. She confronts the professor. While pointing the gun at her, she tells her that she has never forgotten anything, especially the day they were eliminated. Realizing that she is running out of time, Ja-yoon decides to make her creator find her. She shoots the professor's leg and forces her to reveal the location where the serums are being kept.

Meanwhile, the young man realizes that he has been tricked and immediately heads over to the room. However, Mr. Choi and his men show up and start shooting at them. It is also revealed that the young man is actually the kid that Mr. Choi caught earlier. The gunfight ensues, and he orders his men to aim for the head if they want to kill them. The young girl intervenes and starts eliminating all of Mr. Choi's remaining men with her knives. On the other side, the young man suddenly attacks Ja-yoon and challenges her to a duel, stating that he is now stronger than ever. They fight, but the girl is still too fast for him. He can't even land a single punch on her and ends up being kicked by her.

Dr. Baek tries to escape, but Ja-yoon shoots her in the other leg. While she is about to finish the young man, Mr. Choi appears and shoots her. After that, he finishes the professor off. He tries to fight Ja-yoon, but she is just on another level. She outskills him and eventually kills him easily. The young man still doesn't give up while the young girl attempts to stab him, but he sees that coming and finishes her off. At last, she urges the young man to tell her the location of the research facility, but he refuses to do so, so she shoots him. Ja-yoon takes the serums and burns the laboratory down. She immediately heads to the hospital and hands over the serums to her father, as they will slow down the spread of her mother's dementia. Before she goes, her father reveals that he once regretted adopting her, but her mother is the one who keeps assuring him that she would grow into a lovely girl one day if they treated her with love. She then leaves, waving her hand towards her best friend for the last time.

Three months later, Ja-yoon mysteriously shows up at a woman's house, who turns out to be Dr. Baek's sister, demanding her to create a more permanent serum for her.

By:Jamalmustarsyidin