In a restroom in the White House, a janitor finds secretary Carla Town dead. Metropolitan Police homicide detective Harlan Regis, whose apartment block is awaiting demolition in favor of a parking lot, is put on the case. At the White House, Regis is introduced to U.S. Secret Service Director Nick Spikings, National Security Advisor Alvin Jordan, and Secret Service agent Nina Chance. Spikings assigns Chance, a former Olympic gold-class sharpshooter, to keep an eye on Regis.
Parallel to this, the White House has to deal with an impending international crisis: President Jack Neil has been trying to deal with a situation where Americans are being held hostage in North Korea, and some people—including several members of his inner circle, led by Vice President Gordon Dylan—think that Neil is not handling it the right way. Some people think that Neil should send troops to North Korea to rescue the hostages, but he does not want to risk a potential second Korean War.
White House janitor Cory Allen Luchessi was apparently unaccounted for on the night of the murder and had once made a pass at Carla. He is arrested and questioned, but his testimony and a clearly set-up piece of evidence lead Regis to suspect that the Secret Service may be involved. That night, Regis finds his apartment burglarized; the culprit escapes, and in a subsequent search, a hidden bug is found.
In a picture of Carla, Regis sees Burton Cash, the Secret Service agent assigned to Kyle Neil, the president’s son. Regis figures out that Kyle had sex with Carla on the night of the murder. At a dance club, Regis talks with a young woman who says that Kyle once bragged that he shared Carla with his father. Carla’s uncle’s company, Brookline Associates, is the president’s leading East Coast fundraiser, and also owns the apartment that Carla lived in.
Regis eventually discovers that Chance once was Kyle’s bodyguard herself. When he confronts her, Chance explains that one night she discovered Kyle beating up his girlfriend. The Secret Service covered up the beating so that Kyle would not be arrested for assault, and Chance asked to be reassigned and was replaced by Cash. Upon being confronted by Regis, Kyle denies that he murdered Carla, but provides a special piece of information: among the bookings she made, Carla supposedly also ordered a car – despite not having a driver’s license. Later on, Regis and Chance discover that the most recent entries in Carla’s appointment book were forged.
With some clues left by Jordan, Regis finds out that Spikings has withheld several surveillance tapes from the night of the murder. Regis goes to Spikings’ residence to question him; Spikings is willing to show the tape but is suddenly killed by a sniper. However, Regis and Chance escape the gunfire with the tape. They learn that Jordan engineered the murder in order to blackmail Neil into resigning, which would allow Dylan to assume office and have troops sent to North Korea.
Regis, Chance, and Regis’s partner Stengel enter the White House tunnels. The sniper pursues them and wounds Stengel, but Chance manages to kill him. Pursued by the Secret Service, Regis just barely manages to get in contact with Neil and present him with the evidence of Jordan’s conspiracy. Jordan attempts to shoot Neil, only for his shot to be intercepted by a handcuffed Chance, and he is killed by the Secret Service. Chance and Stengel are brought to a hospital, where they recover from their injuries. In gratitude for his rescue, Neil promises Regis to look into the commission who bought Regis’s building.