The sheriff of a small town in southwest Texas must keep custody of a murderer whose brother, a powerful rancher, is trying to help him escape. After a friend is killed trying to muster support for him, he and his deputies - a disgraced drunk and a cantankerous old cripple - must find a way to hold out against the rancher's hired guns until the marshal arrives. In the meantime, matters are complicated by the presence of a young gunslinger - and a mysterious beauty who just came in on the last stagecoach.
Cole Thornton, a gunslinger-for-hire, is hired by wealthy rancher Bart Jason to help him in a range war with the McDonald family in the Texas town of Eldorado, Texas. The local sheriff, an old friend of Thornton, J. P. Harrah gives Cole more details that Jason had deliberately left out, including the possibility of having to side against Harrah. Unwilling to fight his friend, Thornton quits, to the relief of saloon owner Maudie, who is in love with Thornton (and was for a time a romantic interest of Harrah's).
During the final days of the American Civil War, the Union army payroll train is hijacked by Confederates led by Capt. Pierre Cordona and Sgt. Tuscarora Phillips. Their scheme suggests that the Confederates must have gotten detailed inside information about the transport. During the pursuit, Col. Cord McNally’s close friend, Lt. Ned Forsythe, is fatally injured, and McNally vows vengeance. His squad is spread thinner and thinner, until McNally is left on his own. After Cordona and his men capture him, McNally tricks them by leading them into a Union camp and raising the alarm. Cordona and Tuscarora are captured but will not reveal to McNally the identity of the traitor who sold them the information about the train.
In South Los Angeles, a local gang known as Street Thunder steal a cache of assault rifles and pistols. At 3 a.m. on a Saturday in Anderson, a crime-infested ghetto, a team of heavily armed Los Angeles Police Department officers ambush and kill six members of the gang. Later, the gang's four warlords swear a blood oath of revenge against the police and the citizens of Los Angeles.
On New Year's Eve, Detroit Police Department's Sergeant Jake Roenick, veteran cop Jasper O'Shea and secretary Iris Ferry are the only people on site at the soon-to-be-closed Precinct 13. Roenick is deskbound and abusing alcohol and prescription drugs, haunted by a botched undercover operation eight months prior that resulted in the deaths of two members of his team. Psychiatrist Alexandra Sabian is treating Roenick at the station.