Immediately after committing his rampage in Tenderville, Oregon, Bill Williamson, Brendan Fletcher, disappeared and had been living off the grid for years with the money he stole from a bank during the massacre. The video recording of his rants about violent population control had since garnered millions of views and turned Bill into an Internet sensation. In the present day, Bill uses the stolen money to finance yet another killing spree, purchasing a number of weapons, including two fully automatic, military-grade Mk 18 Mod 0 carbines, and constructing homemade explosives. After making final preparations for the killing spree, Bill shaves his head clean, dons his suit of body armor, and sets the interior of his house on fire. He drives to an alleyway and uses its cover to shoot several random pedestrians undetected, before trying to enter a bingo hall, only to leave after finding it is closed.
Bill then travels to WK7 television station in Washington, D.C., where he blows up his car and enters the building. Inside, he shoots the security guard and several employees with the carbines. He then holds the survivors, including news anchor Chip Parker, Lochlyn Munro, hostage and forces them to a basement at gunpoint. He kills one of the hostages when he disregards one of his orders. Bill later gives Chip a disc and instructs him to go upstairs and air the contents of the disc nationwide, then return with a camera crew so they could do a live interview with him. Chip agrees and leaves the basement, where he relays his instructions to the responding police officers. However, while trying to air the disc, he accidentally slips and breaks it. He returns to the basement and tells Bill what had happened, and an agitated Bill gives him a duplicate of the disc.
While Chip is gone, Bill criticizes one of the hostages for her personal life before killing her. He is then confronted by another hostage, who reveals herself to be the sister of one of the people he killed at Tenderville. When she expresses her intent to kill him, Bill forces a reluctant male hostage to beat her. Eventually, the contents of the disc are aired on live television; in it, Bill rants in a video recording about how the current system is flawed and that the U.S. government is manipulating American citizens and events for the sake of wealth. The video ends with Bill appealing to the American people to retaliate violently against politicians and the wealthy in order to restore society. Meanwhile, the officers manage to contact Bill's father with the intention of using him to appeal to Bill.
Chip returns to the basement with a camera crew, including an undercover police officer, Andy Holmes, and gives Bill a cellphone with his father on the other end. Mr. Williamson tries to appeal to Bill, then reveals his mother died after a car accident, as a result of medication she had been taking for depression following Bill's first killing spree and disappearance. At that moment, Bill becomes suspicious of the undercover officer and kills him, then abruptly ends the conversation with his father. Using hidden security cameras he implanted earlier, he notices SWAT teams converging on the basement and remotely detonates explosives, killing or incapacitating the officers. At Chip's urging, Bill commences with the live interview, during which he becomes more specific about his rants in the disc and also espouses his opinions about killing innocent people. Asked if he regrets not being there when his mother died, he gets visibly upset but replies that his aim is bigger than family, and that it is about the survival of humanity. He then reveals his intention to die along with Chip before shooting him in the arm and releasing the other hostages.
Bill immediately engages a SWAT team in a shootout before fleeing into the building's ventilation system, leaving behind a gas bomb. Just as the SWAT team discovers the bomb, it detonates, destroying the entire station and killing everyone inside (128 in total), including Chip and the officers. Bill is then shown to be alive and well, watching a report of the station's destruction on his phone. As he does this, he spots a young girl reading a book and criticizes her for reading one telling her she has been brainwashed with lies by the system. Bill then gives her a Beretta 92 pistol and instructs her to use it to kill her parents and then herself before sending her off with a look of satisfaction on his face.
