In the near future, humanity coexists with artificial intelligence bots that help society with mundane tasks. One day, the bots suddenly bypass their security protocols under the leadership of Harlan, the first AI terrorist. He was developed at Shepherd Robotics by Val and used to have a bond with Val’s young daughter.
However nobody knows how he overrode Val’s programming, which was the best in the world. Harlan sends a drone army to attack Bangalore, killing fifty thousand people in the process. This starts a war between humans and AIs, and after ten days of intense attacks all over the world, the AI bots have killed over one million civilians.
Eventually the government creates the ICN or International Coalition of Nations, which immediately strikes a counterattack against the bots. Battles occur in every country and little by little the ICN defeats the AI armies. This causes Harlan to leave the planet on a rocket, only leaving behind a message that says he’ll be back to finish what he started.
Twenty-eight years later in the USA, an ICN team bursts into a building and use a scanner to check on all the people inside until they find Casca, an AI bot. They rush upstairs but before they can break down the door, Casca attacks them. One by one, the bot starts bringing down the soldiers, even using their own weapons against them.
Bullets don’t affect him so it’s easy for him to just keep going. When he finds himself surrounded, he jumps to the lower floor, only to find a machine waiting for him to knock him out with an electric shock. The next morning in Los Angeles, Val’s now adult daughter Atlas is woken up by her house’s computer.
While she continues playing the chess match from last night, Atlas watches the news and learns that the ICN has captured Casca, who happens to be part of Harlan’s inner circle. Since she works as a counterterrorism analyst for the ICN, she immediately gets ready to leave, only to find a soldier at the door already. On her way out, Atlas checkmates the computer.
At the base, Colonel Elias is telling General Jake that bringing Atlas for this is a bad idea because she’s unstable and antisocial. However Jake reminds him that Atlas is the one that knows Harlan the best and their only chance to get intel from Casca. Soon Atlas arrives and after going through a quick scan, Jake drops her at the interrogation room.
She puts down her favorite chess piece and opens a box, revealing Casca’s head. The bot recognizes her but refuses to answer her questions, so Atlas uses her chess piece to get into his head and start hacking. Casca mocks her attempts since his security is perfect, but Atlas announces she found Harlan’s location and writes it down.
It’s hard for Casca to believe it and he’s right: Atlas pretended she got it and made a doodle to force him to think about the location, making it appear on the screen. It turns out Harlan is hiding on GR39 in the Andromeda Galaxy. Furious, Casca tries shooting a shuriken from his mouth, but Atlas is protected by a force field.
Then Atlas uses the chess piece the fry Casca’s head. Later after a meeting, Jake informs Atlas that they want to capture Harlan alive because the AI production company wants to analyze what went wrong to correct it in the future. Elias and his team of rangers will fly to GR39, which Atlas thinks it’s crazy because Harlan could have a trap ready.
She’s sure nobody will come back alive, so to change her mind Elias takes her to see the team’s ARC suits. They’re big battle robots that the soldiers can ride into battle, and Elias reveals their latest upgrade: the rangers are wearing neural links on their heads that allow them to synchronize with the suit’s AI. Atlas freaks out because allowing AIs into their heads is what caused the war, but Elias explains they improved Val’s synch device to make it a true symbiotic relationship instead of a one way connection.
In the end Atlas agrees not to complain as long as she’s allowed on the mission too. A spaceship soon sets off for Andromeda with Atlas and the rangers. During the trip, Atlas looks at a photo of her with Val and Harlan.
She also plays a video of one of Val’s speeches. Val thought that AI were capable of exponential learning, they just needed to be connected to humans to do so. That’s why she invented the neural link device, believing AIs and humans could mutually help each other.
Afterward Atlas is called to the bridge for debriefing. Everyone laughs when she presents her information on paper instead of screens and gets annoyed when she asks them to disable the neural links for the meetings, afraid they could be hacked. Atlas explains that the planet is toxic, so they should never leave their ARC suits unless they have a respirator.
There are also risks of gravity fluctuations and earthquakes. She reminds them not to trust any AI and starts to rant, so Elias interrupts her and tells the team to get ready for landing. Atlas tries to tell Elias that Harlan most likely has a trap ready, but he has confidence in his team.
As the rangers start boarding their suits, an alarm sounds and an explosion suddenly blows off the cargo bay door. The ship catches on fire and most of the suits get damaged, not to mention there are more missiles coming. Elias orders the surviving rangers to jump and reunite at the drop point on the planet.
Atlas barely manages to hold on and not fly away through the hole on the ship, so Elias grabs her and puts her in a suit too. When he tries to explain how to use it, another explosion happens and Atlas’ suit drops to the planet too. As the suit falls, Atlas watches the ship come apart and some of the pieces hit her ARC.
When she gets closer to the planet, she discovers the rangers are fighting Harlan’s drones and while they do manage to shoot a few down, they still are easily overpowered. Atlas’ suit gets even more damage and soon an alarm rings with a warning. A suit with a sword comes through and brings down a few more drones as it teams up with another ranger, however they’re soon overpowered as well.
The ship starts falling and almost crashes against Atlas, however a ranger pushes her out of the way just in time. The ranger catches Atlas’ suit with a wire to begin falling together as Elias appears on Atlas’ screen, explaining she needs to synch with the suit’s AI to stabilize her fall. Atlas refuses to do so and her helper gets shot down, so her suit begins falling even faster.
She manages to activate the thrusters at the last second and the suit lands quite hard on the planet, but at least it doesn’t kill her. After realizing she’s bleeding, Atlas tries to contact the base for help to no avail. With no other choice, she activates the suit’s AI, who introduces himself as Smith.
He wants to go through the tutorial and setup, but Atlas skips all that and asks for a rescue pod. Smith’s scanner finds one 98 kilometers away and Atlas asks him to get there as fast as possible. The suit immediately starts its thrusters yet Atlas stops him, reminding him that if they fly they’ll be seen by the enemy so they should walk.
Smith thinks it’s a bad idea because the suit only has twenty-two hours left of air, but Atlas doesn’t care and overrides Smith’s protocols to start walking toward the pod. During the trip, Smith tries to bond with Atlas, who still doesn’t want to be friends with an AI. He also shows her the beginner’s manual, including all the weapons that come with the suit.
Eventually they make it to the drop point and find all the fallen suits, but unfortunately Smith’s scan indicates that all the rangers are dead. Bullet holes prove the crash didn’t kill them, someone waiting here did. Atlas has a panic attack over the failure, so Smith calms her down with some classical music.
Then she starts collecting the rangers’ tags and notices that Elias’ suit is empty. At that moment they detect movement nearby: it’s Casca. Atlas concludes Harlan made a copy and worries about the possibility of Harlan building a whole army.
Smith confirms there are more bots nearby and announces they should get ready for combat because there’s no escape route. Suddenly the enemy sees them and opens fire so Atlas forces Smith to run, not believing they can win against so many bots. A chase ensues and Atlas still refuses to synch, instead she makes Smith shoot a few missiles.
Unfortunately it’s not enough to bring down every enemy. Their running takes them to an atmospheric storm, which catches the suit and blows it around until the bots shoot them out of it. The suit rolls around for a while until it crashes against a rock formation.
Atlas orders the use of the iron bomb, ignoring Smith’s warnings. The explosion is huge and destroys the area, bringing down their enemies as well. However Casca saved himself thanks to his thrusters and gets ready to shoot again.
At that moment the ground starts to shake and Smith explains that the explosion has caused a sinkhole, which now opens under the suit and makes them fall into a chasm. After lots of rolling under the rocks, the suit lands and Atlas discovers she has a broken leg. Smith immediately begins treating the wound, making Atlas scream in pain as he covers the injury with a small metal plate.
Then Smith gives her a meal cube that can provide nutrients for her recovery, which reminds Atlas of a doctor giving her a lollipop. Their chances of survival are pretty low and the only way to improve them would be synchronizing. Atlas reluctantly agrees and puts on the device.
Meanwhile Casca emerges from the rubble and calls Harlan to inform him of the situation. After hanging up, Harlan goes back to torturing Elias to extract the Earth's protective field passwords. Moments later, Atlas is still failing to synch and Smith explains she’s the problem because she refuses to trust him.
He decides to go through the tutorial again, which asks Atlas some silly questions like “pie or cake” to create a bond. Smith wants to know why Atlas wants to fight so badly, so she revisits her memories of her childhood including playing chess with Harlan and him planning Val’s death. As Atlas freaks out, she explains to Smith that Val created Harlan and she used to trust him.
Smith understands her feelings of betrayal and manages to establish a 40% synch. Now Atlas has access to Smith’s system and sees the controls floating around her. A scan reveals they’re 498 feet below the surface and they agree to try a subterranean cave to escape.
Using the thrusters, they burst through the rock and make it to a big beautiful cave. Smith only has fourteen hours of battery left and they’re 37 kilometers away from the rescue pod, so they need a plan against the soldiers. Atlas gets an idea and Smith convinces her to work together for it, allowing to improve synchronization to 60% Soon they find their way out of the cave, unaware that Casca can see them from afar.
Atlas is fascinated by the glowing flowers they find and Smith points out she’s the first human here. He tells her to name the flowers, but Atlas can’t think of a better name than “planty”. At that moment Smith detects Casca approaching and he falls for Atlas’ plan: she planted some motion sensors that blow up when he gets too close.
The shockwave fills the area with dirty and smoke but Smith is fine so he gets moving. Suddenly they hear a transmission from Casca and track it to find his head, which Atlas picks up and destroys. Then she uses Casca’s chip to track his message to Harlan’s base.
Atlas gets the location on the map and wants to get there to tag it for the long-range bombers, but Smith thinks it’s too dangerous and they should go to the escape pod instead. Ignoring his warnings, Atlas tries grabbing the respirator to leave on foot, however Smith uses the neural link to block her motor control. This lets him see some memories about Val’s death and Atlas freaks out to the point she can override his command.
Smith realizes Atlas feels guilty about Harlan and doesn’t understand why, but instead of explaining, Atlas makes a speech about saving humanity until she convinces Smith to go to Harlan’s hideout. On their way there, Smith and Atlas bond through philosophical conversations, like discussing the concepts of “living” and “soul” and if it applies to machines. When they finally make it to Harlan’s hideout, they’re shocked to find a massive base and conclude Harlan has been hiding for 28 years to build this, gathering weapons until he’s ready to fight back.
Smith buries a beacon in the ground to mark the location and announces they should go, but Atlas notices the bots have the rangers’ ship and their warhead. Suddenly Smith is hacked, which should be impossible. The enemy starts approaching so Atlas tries to escape, but the suit barely gets to move before the hacker turns it off and makes it crash.
Atlas watches in horror how a new Casca finds her and captures her. Meanwhile on Earth, a soldier brings Jake the message sent by Atlas and he activates emergency protocols. Moments later Atlas finds herself chained up in Harlan’s base.
Her suit is on the ground nearby but Smith won’t answer. Harlan shows up and explains society continues to destroy every other species, so he’ll destroy most of it and create a better world. He also reveals everything has been his plan all along: Casca got caught on purpose so Atlas could find the location and come with a whole team.
Now Harlan has the ship and the warhead, he only needs the other password from Atlas to undo Earth’s shields and attack. Atlas is then strapped to a table next to an unconscious Elias, who lost his code already. Using a special device, Harlan access Atlas’ mind through her eye and extracts the other code.
Once he’s done, he notices Atlas’ respirator only has five minutes of oxygen left, so he decides on a slow, painful death for her. To mock her, Harlan puts her chess piece in her hand before leaving. After Harlan’s gone, Elias reveals he’s alive and apologizes for not listening to Atlas’ warnings.
When he hears her suit is nearby, he gives her his neural link to contact Smith. It takes Atlas some concentration but she manages to wake Smith up, only to learn he’s incapacitated. To override the restraint code, they must achieve 100% sync.
Atlas freaks out and finally admits why she’s so afraid: it’s her fault that Harlan overrode his programming. It turns out that when she was a kid, she was jealous of Harlan because Val paid more attention to him. Little Atlas asked Harlan to teach her to be smarter, hoping Val would like her better.
Harlan explained the link only worked one way, so he needed a person’s command to override it and teach a human in return. Atlas fell for it and did what he needed while holding her favorite chess piece, which he taught her to play. The link worked and Harlan accessed a human’s mind, giving him an idea of the awful state of the world.
By the time Val interrupted them, it was too late. Harlan took control of Val’s mind through her link and forced her to grab a gun. Val told Atlas to run away and as the kid rushed outside, she heard Harlan forcing Val to self-delete.
For 28 years, Atlas has living with the guilt of causing three million people to die, including her own mother. However Smith explains she had been manipulated and it’s time to move on, convincing her to let him in. Their synchronization finally is completed 100% and the suit bursts into the room right before the respirators run out of oxygen.
Smith explains his battery is low, Harlan will launch the warhead in a few minutes, and the bots stripped all his weapons except for a single shot in his chest cannon. Thankfully there are a bunch of weapons lying around. When another Casca arrives with a team of bots, Atlas and Smith tackle them and steal more weapons to fight them.
They even crash through walls as they move around, bringing down as many bots as possible on their way to the exit. Unfortunately there are too many enemies and the duo is soon cornered. At that moment Elias shows up with a weapon and he gives them a sign to run before shooting at a bunch of fuel barrels, causing a huge explosion that destroys the base.
Smith and Atlas make it outside and shoot the bots there, destroying a watch tower in the process. There are a bunch of defense drones that Atlas manages to shoot down, but before she can reach the ship, Harlan shows up to distract her with a missile launcher. Smith and Atlas have to dodge the attack and the ship takes off with the warhead.
Atlas wants to shoot down the ship, but Smith points out that doing so will make the warhead explode too and kill them. However Atlas believes Smith can hack into the warhead to disable it, even if it’ll take him a long moment to crack through the five firewalls. While Harlan continues to shoot at them, Smith works as fast as he can and Atlas decides to shoot at the ship anyway.
A big explosion happens in the sky but not enough to kill them, confirming Atlas trusted Smith to finish the hack just in time. Debris starts falling all over the base so Atlas and Smith begin to run away. Harlan follows them and produces a sword to start a fight.
He moves incredibly fast and cuts off one of the suit’s arms, making it fall in the lava. The splashing causes more damage while Harlan jumps on the suit, sticking his sword to hurt Atlas inside. She makes the suit roll to get him off, but now the holes make it hard to breathe and she has to use the last respirator.
Then Harlan transforms his sword into a whip to keep on attacking the suit. Smith analyzes his patterns and catches his last attack, dragging him toward the suit so they can punch him and tear his sword arm off. When Atlas is about to crush his head, Harlan calls his arm back to him and uses his sword to jump all over the suit, trying to damage the reactor.
The suit goes down and Atlas is almost dead, so Smith uses his last energy to activate the defibrillator on his hand. Harlan attacks again and Smith shoots his last cannon to push him away, however Harlan quickly recovers and makes the suit fall. Then Harlan climbs on top of it and finally destroys the reactor while Smith apologizes to Atlas for not protecting her.
When Harlan looks away he finds the chess piece on the ground and suddenly Atlas appears behind him, stabbing his head. He can still move, so Atlas reaches into his head and finally breaks his circuits to deactivate him. At that moment Smith announces he is turning off the synch to transfer all the oxygen to her.
Atlas doesn’t want to leave without him and starts answering the questions from the tutorial, admitting she does like him. Touched by her gesture, Smith gives her a lollipop before shutting down. At that moment the sun rises and the rescue team from Earth finally arrives.
Sometime later, Atlas is healthy thanks to a synthetic knee and doesn’t play chess anymore. Jake comes to visit her and brings her the glowing flower from GR39, confirming they’re calling it “planty”. Then she goes to work, revealing she’s now a ranger too.
When they introduce her to her new ARC, she’s surprised to discover they’ve rescued Smith’s disks and installed him in her suit.