Uncas says that he will speak in the Delaware tongue. Tamenund expresses doubts about his identity, and one of Tamenund’s advisers claims that Uncas is a false Delaware. Uncas responds defiantly. Tamenund assumes that Uncas is a Delaware who has deserted his tribe. He says that his people can do whatever they want with him. A cry of vengeance goes up, and Uncas must face torture by fire. A Delaware warrior rips Uncas’s shirt off. But then everything stops as the Delawares perceive a tattoo of a tortoise on Uncas’s chest. This indicates that he has a close affinity with the Delawares, who are known as the children of the tortoise. In answer to a question from Tamenund, Uncas reveals that he is the son of the great Unamis (Turtle). Tamenund exclaims in joy, for he knows that only Chingachgook and his son retain the ancient blood of the turtle, the original Indian race, in their veins. Uncas frees Hawkeye and tells Tamenund that the scout is a friend of the Delawares. Uncas then tells Tamenund that Magua has no rights over any of the prisoners except for Cora. Tamenund tries to persuade Magua not to take Cora, but he refuses. Tamenund then grants him permission to leave with Cora. Heyward offers a ransom that will make Magua rich, but he refuses. Hawkeye then offers himself as a prisoner if Magua will release Cora. Again, Magua refuses and readies himself to depart. Uncas grants him a truce until the sun descends to just above the trees.
Uncas sings a war-song and the Delawares prepare for battle against the Hurons. Hawkeye sends an Indian boy to fetch his rifle and the rifle of Uncas from where they had hidden them prior to their entrance into the Delaware camp. The Hurons shoot at the boy, but he returns safely with the rifles. Uncas gives Hawkeye command of twenty men, and wants to give Heyward the same. But Heyward prefers to go with Hawkeye. Uncas gives the word and two hundred warriors set forth into the forest. They stop for a conference on how best to proceed, and then spot what they at first think is a Huron approaching them. Hawkeye is about to shoot him when he realizes that the man is in fact David Gamut. David tells them that the Hurons are out in force, led by Magua. Magua has left Cora in a cavern. Hawkeye comes up with a battle plan designed to rescue Cora. The other chiefs agree to it.
Hawkeye notices that David is following them. David says that he will willingly participate in the coming battle and produces a sling that he knows how to use. Hawkeye allows him to accompany them. They are only half a mile from the Huron camp, but at first there is no sign of the enemy. Then there is a volley of rifle fire, followed by a retreat by the Huron attackers. The Delawares press forward, and the rifle fire from both sides is about equal, but with few casualties. However, Hawkeye perceives that the situation is not favorable for his men. This situation changes when the party led by Uncas makes a successful attack. The battle moves slowly towards the Huron village as the Delawares continue to advance, even though they sustain casualties. A final charge gives them the advantage, and there is hand-to-hand fighting. Chingachgook enters the battle, shooting at the Hurons from behind them, and the Hurons have no response other than flight. Hawkeye gives up his command to Chingachgook, the rightful leader of the Delawares.
Meanwhile, Uncas and his men are engaged in a battle in the forest with the main body of Hurons. The Hurons are forced to retreat as both wings of the Delaware force—one under the control of Chingachgook and the other led by Uncas—press their advantage. But Magua and a small band of Hurons refuse to flee. Uncas sees Magua and rushes after him. The Hurons finally make a stand around their council-lodge. Uncas again pursues Magua, this time into a cavern. Magua emerges with Cora, and the chase continues up a mountain. Cora refuses to go any further, and Magua asks her to choose between becoming his wife and immediate death. As Cora prays and Magua cannot make up his mind about whether to kill her, Uncas leaps down onto the ledge where they stand. A Huron warrior who is with Magua stabs Cora to death. Magua strikes Uncas in the back with his tomahawk. Uncas rises to his feet, but Magua stabs him several times in the chest, killing him. Then Hawkeye kills Magua with one shot from his rifle.
The next day, the Delawares mourn their losses. The Hurons have been completely destroyed. Six Delaware girls attend to the body of Cora. Her father sits at her feet. The corpse of Uncas has been dressed in gorgeous ornaments such as bracelets and medals. Chingachgook sits in front of him. Hawkeye, David, Heyward, and a visiting French soldier silently observe the scene. Tamenund gives a mournful address, then a chant is raised in honor of the dead, and female voices are heard in lamentation. They know that Uncas had been in love with Cora, and they assume the two will be united in the afterlife. They praise both of them. Then Chingachgook speaks in praise of Uncas, and he is followed by other senior Delawares with their tributes. Cora is buried in a nearby knell. David sings a sacred song over the grave. Munro speaks some words of thanks to the women who buried her. Then he, Heyward, and David leave the village and go off into the forest. Chingachgook speaks more words of lamentation and grieves that he is now alone. Hawkeye reaches for his hand and pledges his friendship.
The last chapters bring the interracial theme into clear focus. In Chapter XXX, Cora says it would be a “degradation” for her to be married to Magua and produce children by him. When Magua says “thy race will not end,” she replies, “Better a thousand times, it should.” In other words, it would be better to be extinct than to produce children of mixed race. In giving his character this attitude, Cooper is merely reflecting the beliefs of the age in which he lived.
The situation is made more complex, however, by the fact that Cora herself is of mixed race. Even though the non-white blood in her is far in the past, it is clearly alluded to in the same chapter, when “her dark eye kindled, while the rich blood shot . . . into her very temples.” Once again there is a clear contrast with Alice, whose whiteness Cora envies: “’She is fair—Oh, how surpassingly fair!’ laying her own beautiful, but less brilliant hand, in melancholy affection on the alabaster forehead of Alice.”
In the resolution of the plot, Cooper is deeply conscious of the racial element. The couple that he allows to live and prosper is Alice and Heyward—the perfect match. The problematic triangle of Uncas, Cora and Magua is resolved only in death. It would have been considered too shocking for Cooper’s readers to allow Uncas and Cora to marry. However, Cooper’s sympathies are clearly with them. He leaves it to the Delaware girls who mourn them both to point out that Cora “had left the upper earth at a time so near his [Uncas’] own departure as to render the will of the Great Spirit too manifest to be disregarded” (Chapter XXXIII). The women see no reason to disparage this union in the afterlife, although this is partly because they are aware of Cora’s mixed heritage, the fact that she is not pure white: “Why should not such a predilection be encouraged? That she was of a blood purer and richer than the rest of her nation, any eye might have seen.”