Eddie Kasalivich (Keanu Reeves) is an aspiring machinist who is part of a dedicated team at the University of Chicago, working tirelessly to extract energy from water. Despite their persistent efforts, progress has been slow. However, a breakthrough occurs when Eddie, while tinkering at home, uncovers the method to effectively harness energy through burning hydrogen, with water as the only byproduct. The following day, he successfully demonstrates this innovation in the lab, prompting a celebratory gathering among the team.
As the night unfolds after the celebration, Eddie offers to help Dr. Lily Sinclair (Rachel Weisz), the project physicist, who finds herself stranded with a dead car battery. Together, they venture out in search of a taxi, unaware that danger lurks back at the lab. Meanwhile, Drs. Alistair Barkley and Lu Chen are busy at their stations when they are ambushed by a group of thugs, leading to Chen's abduction and Barkley's precarious situation.
Upon arriving at Lily’s residence, and ensuring she is safe, Eddie heads back to the lab for his bike. There, he spots a suspicious van making a hasty exit before hearing alarms ringing from inside. Racing to investigate, he finds Alistair in a dire state and Chen mysteriously missing. With the hydrogen reactor dangerously unstable, Eddie rushes to stabilize it but is locked out of the system. Realizing the imminent explosion, he narrowly escapes just in time as a concealed detonator triggers a cataclysmic blast that devastates the lab and multiple city blocks.
In the aftermath, authorities, including the FBI, interrogate Eddie regarding the explosion. Returning home alongside Lily, they soon uncover evidence that suggests they are being framed, leading them to go on the run. Their journey takes them to the observatory of Maggie McDermott, an old acquaintance of Eddie's. After a brief respite, they reach out to Paul Shannon (Morgan Freeman), the project’s financier, seeking his guidance, but they barely evade capture during the call.
As Eddie and Lily elude law enforcement, Paul is seen convening with Lyman Earl Collier (Brian Cox) to discuss the explosive turn of events at C-Systems Research. It becomes increasingly clear that the conspiracy to sabotage their project and set them up was orchestrated by the company, with Lyman having ordered the attack. Despite conflicting views, they persist in their pursuit of Eddie and Lily, especially after Eddie sends a cryptic message requesting another meeting.
Upon meeting at the new location, Paul shockingly reveals that he framed Eddie. This encounter swiftly devolves into chaos, resulting in Lily's capture while Eddie manages to flee. Utilizing his knack for deduction, Eddie traces the vehicle used in the ambush back to C-Systems and sneaks in to rescue both Lily and Chen. Seizing the moment when an experimental reactor at C-Systems malfunctions, Eddie quickly seizes control and sets about rectifying the trouble.
The next day, with the reactor operating correctly, caution stirs within Paul. He discreetly backs up the fusion data and subsequently confronts Eddie in a tense members-only space, weighing the choices of letting him go against business interests. Paul concedes, but Lyman's stubbornness proves detrimental when he underestimates Eddie's resolve. As Eddie retaliates by rigging the reactor to blow while transmitting evidence of his innocence and reactor schematics to the FBI, Lyman's aggression leads to the murder of Chen, leaving both Eddie and Lily in grave danger as he plots to let them perish in the explosion.
As chaos unfolds within the facility, Eddie and Lily cleverly navigate their escape from the disaster unfolding around them. Meanwhile, Paul’s action of disabling the containment doors saves the couple, ensuring they triumph over the imminent danger. In the last moments, as they emerge from the wreckage into the hands of the FBI—now aware of their innocence and plight—Paul makes his exit, seen dictating a crucial memo that signals the termination of C-Systems as a functional entity, setting a new course for accountability and justice.
