Detective Tyler Burke (Roger Cross) and his two men infiltrate the house of a drug dealer George Freemont, with whom he had been secretly collaborating to sell police-confiscated narcotics. They ask him for Freemont's proof of their collaboration. They destroy Freemont's laptop, and Burke shoots Freemont after making it look like Freemont shot first.
Detective John Shaw (Dean Ambrose) returns to active duty at his precinct after the death of his partner, Ray Jones, in which Shaw was shot and sidelined with post traumatic stress disorder. He is met by his supervisor, Captain Matthews, recent police academy graduate Officer Jenny Taylor (Sarah Smyth) and lastly Detective Burke, who is being hailed for his 'bust' of Freemont.
Unknown to Burke, Freemont had made a backup containing the incriminating evidence that is in the form of a flash drive in the shape of a credit card, which is found during Freemont's autopsy and delivered to Evidence by Taylor. Shaw reads the incident report of the Freemont bust and retrieves the flash drive from Evidence. At the same time, Burke, at his home, receives a call from Taylor regarding the flash drive. Burke deduces that the flash drive contains the evidence and quickly heads to the precinct. Discovering the content of the flash drive, Shaw heads to Matthews' office. Burke receives word from Officer Meeks, one of his corrupt colleagues, that Shaw had already checked out the flash drive, but misses Shaw though both men shared the same elevator. Burke is unable to intercept Shaw and triggers the fire alarm so that everyone (except he and his fellow corrupt cops) can evacuate the building and find Shaw easily. Once the building is evacuated, Officer Darrow (Lochlyn Munro) takes over security control to monitor Shaw's whereabouts via CCTV and also initiates a total lockdown of the building, disabling all the phone communication, computer networks as well as jamming cell phone signals. Shaw, unable to find Matthews at her office, had ducked into a stairwell to call her on his cell, but is cut off by the lockdown.
Shaw, knowing that he is now being hunted, ambushes Meeks but is surprised by Burke, Shaw uses Meeks as a shield, but Meeks is shot anyway by Burke. Shaw and Meeks duck into an elevator, but Meeks dies soon after. Burke radios Darrow to shut down the elevators, but Shaw manages to escape.
Shaw next runs into Taylor, who had been accidentally locked in. She sees Meeks' blood on Shaw and refuses to trust him, forcing him to draw his gun on her. He confiscated her taser and leaves her with a warning to hide until the lockdown is over. Matthews arrives and hails Burke over walkie talkie. Burke takes the opportunity to frame Shaw, directly blaming him for Meeks' death and assuring Matthews that he will handle Shaw. Shaw then goes into the motor pool where is spotted by Darrow on the camera. In the ensuring pursuit, Shaw is hit by the bullet to his arm while attempting to flee in an unmarked police car, but manages to elude his pursuers.
Taylor next runs into Burke, who invites her to walk with him to the security control. Burke tells Shaw through the PA system to show himself in the CCTV camera or else he will shoot Taylor. Shaw reveals himself and after sending his men after Shaw, Burke shoots Taylor anyway and the gunshot is heard by Shaw.
Burke and his fellow corrupt cops don SWAT armor and weaponry and went out to corner Shaw in a Crime Lab where Shaw had been bandaging his arm. Shaw is pinned down but managed to escape using Taylor's taser to stun a dead corrupt cop to fire an assault rifle that caused an explosion nearby on an experiment table, killing one corrupt cop but narrowly saved Burke and the others. The Police Chief arrives and takes charge of the situation from Matthews, informing Burke that there is a SWAT team inbound.
Shaw heads to the server room and disconnects several wires to disable the CCTV cameras. Shaw then reactivates the network in order to upload the evidence regarding Burke to Internal Affairs. Darrow notices that the network is activated and after alerting Burke, managed to deactivate the network before the evidence is sent. Shaw goes to the rooftop in order to get a signal and make a call to Matthews. Shaw convinces Matthews that he is the innocent and Burke is corrupt. He is interrupted by one of Burke's henchmen and after a brief fight succeeds in escaping again.
Shaw manages to ambush a lone Burke and cuffs him and both men enter an elevator. Burke secretly has its own key and manages to unlock the cuffs and after a struggle, Shaw is forced to escape but not after being shot in the hip. The SWAT Team arrived on scene to prepare for the raid. Shaw then goes to the office again to bandage his hip. Burke and 2 henchmen catch up with Shaw, who succeeds in escaping again. The Police Chief radios Burke that SWAT will enter once they cut the power.
Darrow and Burke manage to ambush and capture Shaw, whom they bring to a meeting room. Burke succeeds in getting the flash drive from Shaw and promptly destroys it. Just as Burke is about to shoot Shaw, the power is cut and Shaw manages to use the distraction to escape.
After a brief encounter with the SWAT Team, Shaw calls Matthews to meet him at the back of the building. They meet up, but only to reveal herself as working with Burke. Burke then shoots Matthews before the SWAT Team bursts inside. As Shaw is about to be arrested, he plays a recording of Burke's earlier monologue in which Burke incriminates himself. Burke attempts to shoot Shaw but Shaw fires his last round to Burke's leg. Shaw then cuffs Burke and walks out of the building.Dean Ambrose as John Shaw
Roger Cross as Tyler Burke
Daniel Cudmore as Gideon
Lochlyn Munro as Darrow Smith
Ty Olsson as Harris
Sarah Smyth as Officer Jenny Taylor
Rebecca Marshall as Captain Matthews
Toby Levins as Meeks
Bill Dow as Police Chief Keppler
Sharon Taylor as Carmen
Matthew Harrison as George Freemont