A fight breaks out as Hawkeye and the Mohicans attack the Hurons, whose rifles have been set aside. In the battle, Uncas saves Cora and Chingachgook becomes locked in hand-to-hand combat with Magua, who escapes only by feigning his own death. Hawkeye and the Mohicans soundly defeat the remaining Hurons and free the prisoners. Chingachgook scalps the dead victims, while Heyward and Uncas ensure the well-being of Cora and Alice. After Hawkeye releases Gamut, they argue about the efficacy of prayer-song. Hawkeye cites the pragmatic necessities of battle to urge the psalmodist to abandon the useless weapon of the pitch pipe. Resisting Hawkeye’s logic, Gamut responds by citing the religious doctrine of predetermination and singing another song. Ignoring the performance, Hawkeye reloads his rifle, and the group begins to travel northward toward Fort William Henry. Hawkeye explains that with the brilliant aid of Uncas he and Chingachgook succeeded in tracking the Hurons for twenty miles.
The party travels to a ruined blockhouse where Chingachgook and Hawkeye won a battle many years before. The memorial site spurs Hawkeye to describe the Mohicans as the last of their tribe. The group, with the exception of Chingachgook, sleeps until nightfall, when sounds of nearby enemies cause alarm. The sounds they hear are made by the Hurons, who have lost their way. Two Indians approach, but their respect for the memorial site keeps them away. After the Hurons depart, the group continues toward the fort.
The group treads barefoot through a stream in order to hide its tracks. They pass a pond, and Hawkeye tells the group it is filled with corpses of slain French soldiers. As they near the besieged Fort William Henry, they encounter a French sentinel. Heyward talks to him in French, distracting him while Chingachgook sneaks up to the sentinel, kills him, and scalps him. Firing breaks out between English troops protecting the fort and French forces, and the crossfire puts the party in danger. Thick fog conceals them, however, and they attempt to find their way to the fort through the sounds of battle. The French forces pursue them, but they arrive at the fort safely. As they enter the fort, Colonel Munro weeps and embraces his daughters.
Five days into the siege of Fort William Henry, Heyward discovers that the French have captured Hawkeye. Inside the fort, Heyward sees Alice, who teases him for not seeing her and her sister enough, and Cora, who seems distressed. Though the French forces eventually release Hawkeye, the French leader Montcalm keeps the letter that Hawkeye carried from General Webb. Montcalm requests a meeting with Munro, but Munro sends Heyward in his place. The French general urges Major Heyward to surrender, reminding him that France’s bloodthirsty Indian allies are difficult to hold in check.
Heyward goes to find Munro, planning to report Montcalm’s message that the English should surrender. He finds Munro idling with his daughters. To Heyward’s surprise, Munro seems uninterested in Montcalm’s proposal. He accuses Heyward of racism for preferring Alice to Cora. Munro reveals that Cora and Alice have different mothers. Cora’s mother, Munro’s first wife, was from the West Indies and was part “Negro.” When Munro’s first wife died, he returned to Scotland and married his childhood sweetheart. Heyward heartily denies that he thinks less of Cora because of her mixed race, but silently he admits his racism. Munro and Heyward return to the French encampment to meet with Montcalm, who hands over Webb’s letter advising Munro to surrender the fort to the French. Montcalm tells Munro that if the English surrender, they will get to keep their arms, baggage, and colors, and the French will ensure that the Indians do not attack them. Munro accepts the offer and leaves Heyward to finalize the details.
After dawn, the English slowly file out of the fort, surrounded by columns of solemn French soldiers and leering Indians. One of the Indians tries to take a shawl from an Englishwoman as she passes by. When she pulls the shawl away from him, he seizes her baby and smashes it against the rocks. Then he sinks his tomahawk into the mother’s skull. Magua begins yelling the frenzied Indian war whoop, and the Indians attack the English, slaughtering them and drinking their blood. Munro storms through the battle to find Montcalm, ignoring even Alice’s cries for help. Magua sees Alice fainting and hurries away with her. Cora chases after him, followed by Gamut, who has been singing throughout the battle in order to confuse the Indians and keep them away from the young women. As the battle abates, the Indians begin looting the bodies of their victims.