In a not-so-distant future, Michael Jennings (Ben Affleck) works as a highly skilled reverse engineer, specializing in analyzing and reconstructing competitors' technology while enhancing it. To safeguard both his clients' secrets and himself, Jennings opts for a memory wipe with the help of his friend Shorty (Paul Giamatti), who has the ability to eliminate specific memories with exact precision. These memory wipes typically follow assignments that last around two months.
When James Rethrick (Aaron Eckhart), Jennings's former college roommate and now the CEO of the prosperous Seattle-based tech firm Allcom, offers him a lengthy, lucrative three-year job, Jennings seizes the opportunity. This contract necessitates him living on Allcom's fortified campus while providing a guarantee of substantial stock options and an eight-figure payout. After making arrangements for his extended absence, Jennings arrives at Allcom, checks in his personal items, and is briefly introduced to the facility, where he has a charming encounter with botanist Dr. Rachel Porter (Uma Thurman).
As Jennings settles into his role, he is implanted with a long-term memory marker, setting the stage for his forthcoming memory wipe upon completion of his work. He is teamed up with Dr. William Dekker and begins the intense process at Allcom. Three years later, as environment shifts and memories fade, Jennings finds himself in Rethrick’s office, where he is thanked for his successful contributions. However, upon returning home, he is shocked to learn that the Allcom stock he should have profited from has become exceedingly valuable, but he had signed away his stakes just weeks before.
As chaos ensues, Jennings finds himself unexpectedly captured by the FBI, interrogated by Agent Dodge (Joe Morton) regarding the suspicious death of physicist Dekker, who was embroiled in classified work. Dodge believes Dekker may have disclosed sensitive information to Rethrick, but without concrete evidence, the only connection to Jennings is the patent applications signed by him, suggesting a haunting link to Dekker's work on a revolutionary lens.
Struggling for answers, Jennings escapes from FBI custody. Utilizing the seemingly random assortment of items he received in a mysterious envelope, he begins to dodge his captors cleverly. While Rethrick is baffled by Jennings's unexpected survival, it's clear something has changed – something that could point to Jennings's potential ability to predict outcomes. After a narrow escape involving clever ruses and calculated risks, Jennings contemplates his connection with Porter, realizing he had built a machine capable of seeing the future, which he had used to alter his fate.
In a harrowing turn of events, Rethrick grows increasingly desperate, even attempting to use a body double to eliminate Jennings. Yet, with Porter's help, Jennings uncovers alarming revelations about their accumulated visions—foreboding glimpses of a future filled with financial turmoil and even nuclear catastrophe stemming from the machine’s predictions.
Determined to avert disaster, Jennings makes his way back to Allcom. He covertly sabotages the destructive machine he helped to create, setting it on a course for explosion while experiencing a final prophetic vision. As danger looms, Jennings outsmarts Rethrick and narrowly escapes the ensuing chaos, inadvertently leading to Rethrick's demise.
In the aftermath, Agent Dodge reluctantly declares Jennings dead in the wake of the explosion. However, the story concludes with Jennings and Porter, along with Shorty, moving forward to cultivate a peaceful life, running a greenhouse nursery where Jennings serendipitously reveals a lottery winning ticket he foresaw through the machine, ensuring a comfortable future for them all.
