Description
In the 1890s, Purvis and Buddy, two drifters who rob and kill travelers, encounter a Native American burial site. They are attacked, Buddy is killed and Purvis escapes.
Purvis arrives in the nearby town of Bright Hope and buries his loot. However, Deputy Chicory reports him to Sheriff Franklin Hunt. Hunt confronts Purvis, who tries to escape, only to be shot in the leg. Hunt sends John Brooder to fetch the town's doctor. Meanwhile, foreman Arthur O'Dwyer rests at home with a broken leg, tended by his wife Samantha, the doctor's assistant. As the doctor is drunk, Brooder calls on Samantha to treat Purvis, leaving her with Purvis and Hunt's other deputy, Nick. That night, a nearby stable boy is murdered.
The murder is reported to Hunt, who goes to the jail and finds it empty, with an arrow left behind. The Professor, an educated Native American, links the arrow to a tribe that he refers to as "Troglodytes", as their culture has no spoken language and hence no name. He warns Hunt that they are a group of inbred cannibalistic savages, disdained and avoided by other native groups. Certain that Samantha, Nick, and Purvis have been captured by them, Hunt prepares to go after the clan with Chicory and Brooder, who is a veteran of the Indian wars. Arthur, despite his broken leg, insists on accompanying them to find his wife.
Days into their ride, two strangers stumble across their camp. Fearing they are scouts for a raid, Brooder kills them. They set up a camp at another spot. However, a group of raiders ambush them, injure Brooder's horse, and steal the rest. The following day a fight breaks out between Brooder and Arthur, exacerbating Arthur's leg wound. Chicory leaves him to recover while he, Hunt, and Brooder continue on-foot.
Reaching the valley, the three men are injured by arrows. After killing two Troglodyte attackers, Hunt and Chicory retreat, leaving Brooder, who is injured and demands to be left behind. Brooder kills one attacker before being killed himself. The Troglodytes capture Hunt and Chicory and imprison them in their cave. The men find Samantha and an injured Nick, imprisoned in a cage. They inform Hunt that the Troglodytes have already killed and eaten Purvis. They witness Nick stripped, brutally scalped, bisected alive, and then consumed. Samantha estimates the number of Troglodytes to be around twelve (reduced to nine by Hunt's posse).
Hunt tricks several Troglodytes into drinking liquor laced with opium tincture. One dies while another becomes unconscious. Arthur follows the men's trail and discovers the valley, he kills two Troglodytes and notices an object embedded in their windpipes. After cutting one out, he realizes that it is animal bone that acts as a whistle. He blows on it, luring another Troglodyte, then kills him.
In the cave, realizing two of their clan were poisoned, the Troglodyte leader grows angry. They cut open Hunt's abdomen, shove the heated opium flask into the wound, and shoot him. Arthur arrives and kills one of them while Hunt decapitates the leader. Arthur frees Samantha and Chicory, while a mortally wounded Hunt stays behind with a rifle. He promises to kill the surviving cannibals when they return, to prevent them from terrorizing Bright Hope. As the three leave the cave, they see two pregnant Troglodyte women, who are blinded and have had all their limbs amputated.
Arthur blows on the Troglodyte whistle with no response and they hear three gunshots, implying that Hunt has killed the remaining cannibals.
