Delusional mental patient Gunther Wyckoff escapes from an institution, determined to locate psychiatrist John D. Faron, whose testimony helped send him to the asylum. He arrives by bus in Terminal City and, in a brutal display of force, uses a Colt pistol to shoot and kill the bus driver when confronted about the weapon.
Wyckoff’s search for John D. Faron leads him first to the doctor’s office and then to his residence. Leaving the apartment building, he spots the Oasis Bar across the street and decides it will serve as an ideal vantage point to monitor the entryway. Inside, the bar is tended by Chuckles and his assistant Skip. Skip’s wife is in the hospital, adding a personal stake to the tense situation. When Chuckles notices a news flash about Wyckoff on the TV, he recognizes the man and attempts to reach a hidden pistol behind the bar, but time runs out.
The four patrons at the Oasis Bar become witnesses and focal points in the standoff: the slutty barfly Freddy, a young woman named Helen who is accompanied by an older man named Earl, and newspaper reporter Harrison D. Barnes. As Wyckoff circles the room, he shoots Chuckles while the bar owner is trying to call for help. He then forces the patrons to take seats at a single table, keeping a steel gaze on them as a grim audience to his demands. The chaos outside the bar spills into the street, and a beat cop is wounded when Wyckoff fires in the officer’s direction. Bystanders rush to aid the fallen officer, and reinforcements are alerted.
Wyckoff telephones the police, insisting they stay back but deliver John D. Faron to the bar within 25 minutes, or he will begin picking off hostages. The press multiplies outside, turning the scene into a live broadcast as the crowd swells. Faron is located and brought to the Oasis Bar, where he attempts to intervene, though the police captain harbors resentment toward Faron for having defended Wyckoff in court, believing that it reduced the offender’s sentence. The plan to bring Faron in secretly fails when Wyckoff detects their approach and wounds another officer.
With a narrow window left, the police prepare to storm the bar, but Faron steps forward first to plead with Wyckoff, hoping to persuade him to release the hostages. The attempt ends tragically as Wyckoff shoots Faron dead. The bar’s ringing phone finally stops the moment of suspense—the hospital calls about Skip’s wife—and Skip battles Wyckoff in a desperate bid to answer. At the same time, police explode a charge and plunge the bar into darkness. In the ensuing confusion, Freddy seizes Chuckles’ concealed pistol and shoots Wyckoff. The deluded fugitive staggers outside and is killed by police gunfire. Kneeling over John D. Faron’s body, the police captain mutters a somber line: “How far does a man have to go to prove that he's right?”
