The pre-credit sequence opens with Commissioner Kirby [Richard H. Cutting] and the last survivor of his U.S. Cavalry escort, who is shot and scalped by Taslik [Keith Larsen] and his squaw Wanima [Joan Taylor]. The film proper then follows Lt. Billings [Robert Stack] as he leads a patrol that has escorted Cpl. Hamilton [Charles Nolte], a cartographer mapping the frontier. On the return to the fort they are ordered to meet Commissioner Kirby and his party at a trading post to carry a recently signed Indian treaty from Washington to the village chief. The treaty is handed to Lt. Billings, who insists the messenger join the patrol, and the group sets out with a nine‑day window to reach the chief before any fresh uprising could spark.
At the trading post is Taslik [Keith Larsen], who offers to guide the column to the chief. He wears war paint and explains it comes from past killings of rival tribes who trespassed on his land, signaling a readiness for force rather than peace. Shadowing the party is Wanima [Joan Taylor], a figure with her own plan, and she acts as a catalyst in the patrol’s evolving dynamic. The patrol grows aware that Kirby and his party have already fallen, though they remain unaware of the details, and the mission to deliver the treaty takes on an urgent, fragile rhythm.
Unknown to the travelers, Taslik and Wanima are actively undermining the expedition. They sabotage the patrol’s supplies in various undetected ways, muting the group’s sense of security as they push forward toward the village. Along the way, the patrol uncovers the remains of Commissioner Kirby’s escort, a grim reminder of the risks they face and the potential cost of failing to maintain vigilance. The discovery sharpens the tension within the group, especially as trust frays and every decision grows heavier with consequence.
With dwindling resources and dwindling time, Lt. Billings must make hard calls. He gathers the last of the water and entrusts a single bottle to Trooper Clancy [Douglas Kennedy], sending him to make a perilous overland dash to the Indian village while the rest conserve strength by moving only at night. Wanima ambushes Clancy and kills him, but she is wounded in the encounter and left unconscious, shifting the balance of power within the patrol and raising questions about who, if anyone, can be trusted.
As night falls, the survivors learn what has happened but Billings refuses to shoot Wanima, a choice that sows dissatisfaction among the remaining troopers who have already faced poison‑water and suicide within their ranks. Wanima agrees to guide the group toward water, yet she instead leads them to an abandoned gold mine, a revelation that ignites renewed tension and distrust. The presence of gold tempts some troopers to deviate from their duty, and Tolson [Peter Graves], Grady [Robert J. Wilke], and Martin [James Parnell] begin plotting to seize the treasure and flee the frontier.
A violent confrontation erupts as the divided men clash, and in the end only Lt. Billings and Wanima survive the onslaught. They press on through the perilous landscape and finally arrive at the village to deliver the treaty, their journey marked by hard choices, scarce resources, and the shaky thread of peace that now rests in their hands. The mission’s fragile outcome hints at the complexities of mediation on the frontier, where every ally can become a liability and every act can tilt the balance toward war or peace.
