The development of the Gatling gun is imagined in this fictional, Western tale.

After the Civil War, Reverend Harper, accompanied by his Apache stepdaughter Leona, disgraced soldier Sneed and another soldier, attempts to dispose of a Gatling gun that has been stolen from the cavalry, hoping that destroying the powerful gun will prevent further bloodshed between the soldiers and the Apache. After Sneed places the gun in a deserted mine shaft and lights the fuse to some dynamite, the explosion attracts a cavalry contingent, headed by Lt. Malcolm Wade. Harper and Leona separate from Sneed and the soldier, who is killed when a rifle shot causes dynamite he has hidden in his shirt to explode. Sneed, Leona and Harper soon are apprehended, after which Harper reveals that they have destroyed the gun. Malcolm's men then go to the mine shaft, where they find the gun still intact. Malcolm insists that the reluctant Harper remain with them and hide the gun in his wagon as they ride through Apache territory because he is considered their friend. By nightfall, when they are about to stop at a fortified ranch, shots ring out, wounding one of the soldiers. Assuming that they are being attacked by Indians, Malcolm, his trusted black friend Runner and the other soldiers shoot back until Gunner deduces that the gunshots are pistols, not rifles that the Apache use. Calling a cease-fire, Malcolm calls out to the inhabitants of the ranch and learns that they are the Boland family: father Luke, his son Jim, daughter Martha and their cook and handyman, Tin Pot. Apologizing that, in the darkness they could not take chances on renegades, Boland invites Malcolm and the others in. Soon after, Apaches attack the compound. Several Apache and soldiers are killed, but Malcolm's life is saved by Martha, who is a crack shot. After the Apache set all of the soldiers' horses free, Harper runs out into the open and hysterically calls to Two-Knife, the leader of a group of renegade Apache, crying out "It's your friend," but he immediately is killed by an Apache arrow. As the Apache ride away from the ranch, Malcolm tells Boland that he must commandeer the family's two horses, which had been secured inside. Meanwhile, Leona sneaks off to where Sneed is being held and loosens his binds, then they kiss and talk about the gold that they hope to receive from delivering the Gatling gun to Two-Knife. The next day, the Bolands join Malcolm and the others and head toward the garrison. Because the wagon is such a heavy load for the two remaining horses, Malcolm soon orders everyone to walk alongside. As they continue, Martha learns from Runner that he had worked for Malcolm's family for many years, including fighting alongside them during the Civil War, and that Malcolm is made of "fine stuff." That afternoon, Malcolm sees a lone Apache following them from a hillside and points him out to Boland. During the night, the sleeping party is awakened by screams from a young soldier on guard duty who has been tied by the Apache to a tree and is about to be engulfed in fire. The soldier's older cousin tries to go to him but it is too late. As the flames reach the young soldier, he begs not to be burned, prompting Malcolm to shoot and kill him. The next day, when Tin Pot is asked by Malcolm to examine the Gatling gun, he discovers that the firing pin is missing. Suspicious that Sneed has the missing firing pin, Malcolm has him searched. Although Sneed does not have the firing pin, the search uncovers a small bag of gold nuggets, which Tin Pot deduces is White Mountain Apache gold. Just then, an Indian approaches carrying a white flag. The man is soon revealed as Two-Knife, who speaks both English and Spanish, and tells Malcolm that Sneed will die but that he will let the others live if they turn the Gatling gun over to him. Two-Knife then leaves, and that night, while everyone is preparing for the coming battle with the Apache, Leona sneaks over to see Sneed. Sneed accuses her of taking the firing pin, which she adamantly denies. He then tries to search her, prompting her to draw a knife on him, after which he knocks her unconscious and escapes. Meanwhile, Martha makes a play for Malcolm by donning a low-cut dress and lamenting that she may never be able to wear it again. Just as she throws her arms around him, one of the soldiers discovers Leona and calls out. Leona lies that Sneed knocked her out when she refused to leave with him. Malcolm then confides in Boland that Sneed will certainly tell Two-Knife about the Gatling gun and they may be doomed. The next day, Sneed, who has been captured by Two-Knife, reveals that the gun does not work and tries to make a deal with him. Meanwhile, Malcolm and the others have found cover on a craggy hillside where Tin Pot has been able to fashion a temporary firing pin from a nail. When the Apache attack, the Gatling gun quickly kills most of them, forcing the others to retreat. After the battle, Tin Pot tells Malcolm that the makeshift pin has broken and cannot be fixed. Because the Apaches do not know that the gun is now broken, Malcolm devises a plan of attack, rather than waiting to be slaughtered. Utilizing their ample supply of ammunition, the men fill empty bean cans with gun powder to make explosive devices. Malcolm, Boyd and the soldiers then sneak to the Apache encampment and lob the cans at them. During the ensuing chaos, Sneed tries to kill Two-Knife but his attempt is seen by another Apache, who kills him. The next morning, Leona tells Jim, who was ordered to stay with her and Martha, that she is going to leave. As he stands up to try and stop her, he is shot to death by an Apache rifle. When Malcolm and the others arrive a few minutes later, they see the fleeing Leona being tackled by Martha. At the same time, the approaching Two-Knife sees the women fighting and orders one of his men to "kill the Americana," but he accidentally shoots Leona instead. As Leona's body rolls down the hill, Martha follows to see if she is still alive. Leona is dead, but when Martha examines the body, she finds the missing firing pin. Martha then rushes back to the others, enabling Tin Pot to assemble the firing mechanism in time to kill dozens of Apache, while Runner and Boland throw the remaining cans. When the Indians retreat, Malcolm sadly observes the dead bodies and muses that they never had a chance against the gun. Malcolm then goes toward their bodies and encounters Two-Knife. Although Malcolm takes aim at him, when he looks into Two-Knife's grief-stricken eyes, he cannot fire. Two-Knife then takes off the cavalry jacket that he had worn as a war prize and walks away.