The Signal

In the near future, sea levels rise because of rapid climate change, and humanity decides to move to space. They build shelters between Earth and Moon's orbital planes and spend decades moving most citizens there. After humanity has settled down, shelters 8, 12, and 13 declare themselves the Adrian Republic and they begin attacking the other shelters, kicking off decades of war with the Allied Force. Now the humans left on Earth have to live building munitions and parts for the robots used in this war. The best soldier in the army is the legendary Captain Jung-Yi, who is currently in an abandoned town and waking up from an explosion. There are robots coming after her and she immediately defends herself with precise shots and creative use of the hook that comes with her weapon. The humanoid robots are easy for her to defeat, but soon a new sturdier model on four legs appears, which will be harder to fight alone. Jung-Yi chooses strategic hiding spots and surprises the robot with a shot that lights it on fire, but the robot has its own set of extinguishers and is soon ready to go again. Using the hook, Jung-Yi piles a bunch of metal beams together and drops them on top of the robot when it comes closer, effectively trapping it. Then she hides behind a car to do her final shot, only to get distracted by a little doll hanging on the car's rear mirror. This distraction allows the robot to shoot her first, and Jung-Yi is pushed back, but when she looks at her broken hand she discovers she's an android and didn't know about it. Suddenly an alarm rings and the town disappears. It turns out this isn't the real Jung-Yi, she actually died in combat some years ago. Now a group of scientists is using a copy of her brain to try to create the perfect soldier android that could be multiplied and sent to war. There hasn't been much progress because during the simulations, which recreate Jung-Yi's last battle, she always loses in the same spot and they don't know why. The head of the team is Jung-Yi's own daughter Seo-Hyun, who has to watch the face of her mother die over and over. There's also Sang-Hoon, the director of the project, who decides to make a special presentation for the higher-ups of the army to promote their android, which they're calling Jung-E. Sang-Hoon's presentation includes fancy dining and a summary of the history behind the war, but the soldiers are bored by this and want him to fast forward through what they already know. The video explains how they're mapping Jung-Yi's neural cortex and converting it to data to develop the most advanced combat command AI ever, then Seo-Hyun demonstrates how the simulations have been recording behavioral patterns. However the soldiers notice the android hasn't escaped the simulation yet, and the entire point is that if Jung-Yi hadn't lost that battle, they would've already won the war. Until the team doesn't solve Jung-Yi's final mistake, the government won't be interested in funding this project. After the presentation is over, Seo-Hyun and Sang-Hoon have a meeting in private. Sang-Hoon reminds Seo-Hyun that she has his full support and that the chairman expects great things from her. He started working for the chairman ten years ago, but he knows Seo-Hyun was taken in when she was just a little girl that lost her mother, so it matters to Sang-Hoon to have a good working relationship with her. Afterward Seo-Hyun works with newbie Jae-Kyung to see what's the problem with their latest model. The remaining scraps of Jung-Yi are awakened and since the brain still thinks as human, the fake Jung-Yi freaks out at seeing herself as a robot and begins agonizing in pain. Seo-Hyun immediately turns off the pain sensors, allowing Jung-Yi to go for fury instead, and she demands to know what they did to her. It seems this copy of the brain is too damaged to keep working on it, so Seo-Hyun orders its destruction. Now they're done for the day, Jae-Kyung takes the chance to express how excited he is to work here because he's always been a big fan of Jung-Yi, calling her a hero. Seo-Hyun explains that Jung-Yi never wanted to be a hero, she only joined the war as a mercenary to pay for Seo-Hyun's treatments because when she was a child they found a tumor in her lungs. She cried every time her mother went to battle, and the day of her surgery was also the day her mother died. Sometimes Seo-Hyun wonders if her mother regrets making such a sacrifice and resents her for it, causing Jae-Kyung to point out she could just ask the android, since she shares the real Jung-Yi's memories. Seo-Hyun says she'll consider it, but it seems she's scared to try. Then Seo-Hyun leaves for the day and takes the local train, where she sees a mother interacting with her child. This makes her remember the last day she saw her own mother: Seo-Hyun had been getting ready for surgery, and Jung-Yi stopped by to wish her good luck before leaving for battle. Jung-Yi had promised she would come back and hugged Seo-Hyun tightly, giving him a lucky cheek rub. When the train makes it to its destination, Seo-Hyun goes to take her annual ethics test that everyone must take to prove they aren't an android, consisting of questions related to feelings and morals. Afterward, she goes to see her doctor, who sadly confirms the tumor is back in her lungs and she only has three months left. This means the surgery she has as a child and her mother's sacrifice had been in vain. The doctor points out the best course of action would be to copy her brain right away and transfer it over to a prosthetic body, since laws protect people that do this nowadays. However they only protect people that do this with type A, which is incredibly expensive. There's also type B, which is cheaper but loses rights like marriage, freedom of movement, and adoption; and the government requires compliance that she will allow them to access her brain data. Or she could choose type C, which doesn't treat people as humans at all; it surrenders ownership of the brain data, allowing certified companies to own it. This means they'll make thousands of clones and the person using this option will no longer be an individual, but at least the prosthetic is free. Type C is what Jung-Yi had chosen to get the surgery money for her daughter. Seo-Hyun promises she'll think about it and leaves the doctor to recharge, because he's an android as well. As Seo-Hyun leaves the building, she remembers the day the company's higher-ups came to her house and asked her grandmother to sign the agreement that would allow them to use Jung-Yi's brain on androids, in return they'd pay for Seo-Hyun's upbringing. They also gifted Seo-Hyun an action figure of Jung-Yi, promising that her mother would be a hero forever, but to this day Seo-Hyun is still unsure that was the best decision. Seo-Hyun ends her day by visiting her mother's comatose body, which is kept in a special chamber so the brain won't rot. The next day, Seo-Hyun's team makes a new copy of the brain and gets ready to test it on a new simulation. But first Sang-Hoon wants to do something different to try to get a new result, and he orders the team to shoot the android in the leg before they start. When Jung-Yi wakes up in the simulation, she suffers great pain from the leg wound, and it hurts Seo-Hyun to watch how her mother suffers. Jung-Yi tries to fight through the pain, but she's easily overpowered, and her will to fight starts to go down. However when the enemy is about to kill her, a new area in her brain lights up, and Jung-Yi stands up to keep fighting, managing to defeat the robot with just her fists before she gets shot by a different enemy. It's a pity that they've lost this new brain already, but Sang-Hoon is excited by this development and is ready to show it off to the higher-ups. The next day, the whole team leaves the labs and travels to the company headquarters, but the chairman isn't available. Instead they're met by the new head of the Product Development Department, who keeps giggling at Sang-Hoon and not taking him seriously. Sang-Hoon is confused by the need for a product development department because they never had one before since the company only produces weapons, and he worries about the possibility that weapons development will be downsized, but his concerns aren't heard and the team is sent away without answers. On the trip back to the labs, Sang-Hoon keeps insulting the new employee and swears he'll keep the chairman's dream alive. Some days later, the team is looking at the new parts they could use for their next android test when they're informed the chairman has come to see them. On the way to the meeting, Sang-Hoon asks if Seo-Hyun has been taking her ethics test because it's important for them to be sure she's doing fine mentally while dealing with her own mother as an experiment. As soon as the pair enters the office, Sang-Hoon freezes, revealing he's actually an android that the Chairman built by replicating his own brain, but Sang-Hoon has no idea. The Chairman has come to bring very important news: the Allied Force and the Adrian Republic are signing a treaty, meaning the war is over and weapons won't be needed anymore. He doesn't consider the research they did on Jung-Yi pointless though because it's taught them a lot about developing good AIs and they can use it now to make housekeeping and service worker androids. The Chairman confesses his original plan was to transfer his real brain into Sang-Hoon to achieve immortality but in the end, he copied it instead because he didn't dare to live inside a machine, which would never stop feeling fake. Seo-Hyun doesn't care how fake it may be, she wants to continue with her mother's project, but the Chairman turns down her request. A few hours later, the team goes back to work, since the project must be wrapped up properly before they change goals. Jung-Yi keeps dying at the same spot and Sang-Hoon becomes furious because they can't activate that new brain area again to isolate it, so he thinks it's time for some extreme ideas. Sang-Hoon makes the team activate the android and cut her arm, thus Seo-Hyun has to watch her suffer as the pain area of her brain reaches excruciating levels. The new brain area still won't light up though, and a desperate Sang-Hoon tries to shoot the android's legs next to match the wound from the other day. Seo-Hyun finally snaps and turns the system off to stop Jung-Yi's suffering, causing an enraged Sang-Hoon to threaten her with his gun. This isn't enough to scare Seo-Hyun and she stands her ground, but before Sang-Hoon can go too far, another employee comes to inform him the Chairman wants to see him. Sang-Hoon leaves without a word, and Seo-Hyun thanks her team for all their work. It's time to shut down the project, but she does ask them to assemble all the data they've collected and send it to her. Sometime later, Seo-Hyun ignores the pain she's feeling in her lungs and concentrates on looking at the data. To her surprise, someone has exported her mother's brain one last time without her knowing. Seo-Hyun goes to investigate and when she walks by Jae-Kyung's room, she hears some naughty noises and makes her way inside. What she finds there it's pretty disturbing: Jae-Kyung had been getting frisky with a new android designed to do dirty deeds but still wearing Jung-Yi's face. After covering the android with a blanket, a furious Seo-Hyun pushes Jae-Kyung against the shelves and insults him for being a pervert, but Jae-Kyung explains he was just following orders. It turns out that making household AIs includes creating companions capable of intimacy, and since Jung-Yi was so popular, people would pay big money to have her as their girlfriend. After all, Jung-Yi's persona is type C, meaning she can be used by anyone. Devastated by the news, Seo-Hyun leaves the room in tears, realizing how she should've seen this coming when they gifted her an action figure of her own dead mother. A moment later, Seo-Hyun is back in the lab to spend time with the android before the project is taken away. Sang-Hoon is already there, suffering from depression because he thinks he lost the Chairman's trust and that's why their project got canceled. Seo-Hyun ignores him and enters the android chamber, waking her up after shutting down the pain sensors. Once she has Jung-Yi's attention, Seo-Hyun tells her they've rescued her from the enemy and that she's greatly wounded, thus she'll help her die peacefully. When Seo-Hyun is about to turn her off, the brain area they had been looking for finally lights up again as Jung-Yi asks if her daughter survived the surgery. Seo-Hyun begins crying as she realizes both times this brain area reacted because Jung-Yi believed she would die without knowing about her daughter, and she tells her the surgery was a success so she can move on in peace. Jung-Yi is relieved to hear this and admits she's been feeling guilty because during the battle, she lost the little doll her daughter gifted her before leaving for the surgery, which was supposed to be a good luck charm. That's why she always loses at the same spot: what distracts her is seeing the little doll in the car and being haunted by the guilt. Not being able to hear this anymore, Seo-Hyun turns her off and has a full breakdown, screaming with her own guilt. Once that's out of her chest, she realizes there's one last thing she can do. The next day, Seo-Hyun requests to do a last simulation before shutting things down. She tells the other team members she'll set things up alone, and once they're gone, Seo-Hyun deletes the unidentified part of Jung-Yi's brain. Then she proceeds to whisper in her ear, explaining all the nasty things that will happen to her after the last simulation is over if they don't do something. When the final simulation starts, Jung-Yi goes through the usual battle tactics and dies in the same spot as usual. Jae-Kyung detects some weird readings indicating the brain's response was weaker, but Sang-Hoon doesn't care because the project is over anyway. The other employees take the android away and Sang-Hoon begins making his way to his room when he suddenly realizes he also saw something strange. He rushes back to the lab and asks for the simulation to be replayed in slow motion, this allows him to confirm Jung-Yi hadn't actually been shot. She only pretended she had and fell on the usual spot. Sang-Hoon immediately activates the alarm and Jung-Yi reacts by knocking out the employees that were taking her away. While everyone gets ready for emergency measures, Seo-Hyun runs back into the lab and deletes all the original project data. Jung-Yi searches for a way to escape and comes across a room filled with dozens of robots that look like her. Before she can come to terms with this, Sang-Hoon's army of security robots finds her, triggering a vicious fight. Jung-Yi is a legendary fighter for a reason though and she easily beats them all up. Even when a robot pushes her against a maintenance machine, she takes the chance to turn it against her attacker. Suddenly, one of the robots takes advantage of her blind spot and kicks her from behind before pushing her against the wall to kill her. At that moment, Seo-Hyun finally shows up and disables the robot just in time. Then she tells Jung-Yi they're in this together, and Jung-Yi trusts her because it's the voice from her dreams. Minutes later, a new wave of security robots arrive at the hangar, and they allow a fellow android to take Seo-Hyun away before they shoot at Jung-Yi. However when they check on the body, they discover Jung-Yi's body is empty. Checking the security cameras reveals Seo-Hyun took the brain copy from the regular body and transferred it to a security android to escape unnoticed, leaving the body with her mother's face behind to trick security. Seo-Hyun drags Jung-Yi into the train, only to discover it isn't as empty as she thought: Sang-Hoon is there waiting for them. As the train takes off, Sang-Hoon accuses Seo-Hyun of being ungrateful for everything the Chairman's done for her and tells Jung-Yi to step away from her daughter. Hearing this is her little girl shocks Jung-Yi, but Seo-Hyun cuts in to explain she's deleted all the data about herself from her memory so she can have a fresh start without any more sacrifices. As revenge for ruining the project, Sang-Hoon shoots Seo-Hyun in the shoulder, prompting Jung-Yi to attack him in return and shoot him with his own gun. Sang-Hoon quickly stands up to keep on fighting, but freezes when he sees his reflection in the window: the damage from the shot has revealed his identity as an android. Seo-Hyun calls him "the Chairman's little toy" and this makes Sang-Hoon go crazy. Now he can activate the abilities of his android body and Sang-Hoon attacks Jung-Yi, starting the fight that throws their bodies all over the cabin and causes the train to shake on the rails. After exchanging a few hits, Sang-Hoon manages to push Jung-Yi through the window, but she lets go on purpose to crawl around the train and re-enter it through a different window. At that moment, more security robots arrive on a parallel train and they attach both wagons together. They come after Jung-Yi by jumping through the windows too, but Jung-Yi has no trouble defeating them all with precise strikes. Sang-Hoon takes advantage of this distraction to catch her with a hook, and when Seo-Hyun sees her mother in trouble, she tries to stop the robot from attacking her. The robot simply pushes Seo-Hyun away, but seeing her daughter in danger inspires Jung-Yi to become more aggressive. She destroys all the remaining robots and kicks Sang-Hoon out of the train, but he manages to make his way back inside by holding onto the hook. As Sang-Hoon and Jung-Yi begin fighting again, the train makes it to the city, and the shaking of two attached wagons becomes too much for the tracks to bear. Seo-Hyun manages to put her hands on one of the weapons the robots dropped and shoots a hook for Jung-Yi to grab, this way she helps her mother return to the first wagon safely and they let the second wagon fall with Sang-Hoon inside. The train finally stops working when it makes it to the mountain area. Jung-Yi wants to take care of Seo-Hyun's bullet wound, but they can hear the police approaching, so Seo-Hyun explains she doesn't have much time left anyway. She wants Jung-Yi to run away and start a new life where she can finally worry about herself instead of her daughter. After some hesitation, Jung-Yi accepts this plan, but first she says goodbye by hugging Seo-Hyun and giving her a lucky cheek rub like when she was a child. As Jung-Yi leaves the train, Seo-Hyun wishes her good luck and dies alone yet feeling she's achieved closure. Jun-Yi runs through the mountains, away from any humans that may want to use her again to enjoy her newfound freedom.