In the year 2084, Douglas Quaid, played by Arnold Schwarzenegger, is a construction worker living on Earth, married to Lori, who is employed by a corrupt mining corporation. Haunted by dreams of visiting Mars, he decides to try Rekall, a company that specializes in implanting memories of vacations that never happened. Despite warnings from a coworker, who shares a cautionary tale about a friend nearly suffering a lobotomy there, Quaid chooses a fantasy trip to Mars, even selecting the exhilarating option of being a secret agent unearthing alien technologies.
During the implantation process, things spiral out of control as the technicians uncover evidence that Quaid has already experienced a memory wipe. Panicking and confused, he believes their actions have exposed him, leading him to attack the staff in a desperate escape attempt. They subdue him once more, erasing any recollection of that day and sending him back home.
Upon awakening in a taxi, he has no memory of the journey. However, disaster strikes when he is ambushed by former colleagues warning him against visiting Rekall. In the chaos, he defends himself, inadvertently killing his attackers. Arriving home, he attempts to confide in Lori, only for her to turn against him, revealing she isn't his real wife—a shocking revelation that prompts him to flee from his apartment.
As he goes into hiding, a mysterious man hands him a briefcase, claiming to have been his ally. Inside, Quaid finds money, a disguise, fake identity papers, and a device to remove a tracking chip embedded in his head. Alongside these items, there's a video message from his past self, identifying him as Hauser and detailing his former life working for Vilos Cohaagen, the Martian administrator. [Hauser] had been involved in hunting rebels but betrayed Cohaagen after aligning with their cause. He believes Cohaagen is the one responsible for his memory loss and instructs Quaid to seek him out on Mars.
Once on Mars, Quaid follows leads that guide him to Venusville, a lawless district riddled with mutations from radiation exposure. Inside a bar named The Last Resort, he encounters Melina, Hauser's former lover, who is skeptical of his intentions and refuses to help him, suspecting him of betrayal. Later, [Lori] returns with Dr. Edgemar, played by Roy Brocksmith, the creator of Rekall. They convince Quaid that his experiences are simply a delusion from defective memory implants. Just as he begins to believe them, Quaid spots Edgemar's anxiety and, in a moment of self-preservation, kills him.
With the threats mounting, [Lori] comes to eliminate him, but with the help of [Melina], who has since aligned with him, Quaid defends himself and eliminates her before escaping deeper into the chaos of Mars. Together, they join a band of rebels who are fighting back against Richter and his forces sent by Cohaagen, who orders the air supply to Venusville to be cut off.
Quaid and Melina, along with a taxi driver named Benny, navigate the perilous environment to reach the rebels' headquarters. There, they meet Kuato, a small but powerful figure physically connected to another man named George. Kuato delves into Quaid's mind, uncovering knowledge about a hidden alien reactor capable of producing breathable air for Mars, a secret Cohaagen has desperately concealed.
The impending attack by Cohaagen's forces leads to devastation; [Benny] is unmasked as a traitor, slaying Kuato and capturing Quaid and Melina. Cohaagen reveals another video from Hauser, explaining that Quaid's entire journey has been a trap to dismantle the resistance. He orders Quaid's return to the Hauser identity and plans to reprogram Melina as his loyal wife. Yet, with grit and determination, Quaid and Melina escape their clutches and rush towards the alien reactor.
In a climactic showdown, Quaid reaches the control room before Cohaagen, who threatens destruction. With quick reflexes, Quaid hurls away an explosive device that breaches the room’s seal, leading to Cohaagen's death via asphyxiation. Just in time, Quaid activates the alien technology; as it erupts with air, a new atmosphere envelops Mars, liberating its inhabitants. As they step into the refreshing air, Quaid reflects on the reality of his experience, questioning its authenticity, before leaning in to kiss Melina against the backdrop of a changing Martian landscape.
