The events of the books take place during the violent wars between Britain and France for the American lands. The native Indian tribes are ruthlessly used by both sides and the inner tension between the different tribes is exploited to make Indians a free cannon fodder. The times are harsh and cruel, danger lies everywhere besides the well-guarded forts and settlements.
But two brave daughters of the old Colonel Munro, the commander of Fort William Henry, sieged by French army, are really worth their father. Escorted by one of the most trusted officers, Major Duncan Heyward and guided by a native man named Magua, they go from the safety of neighboring Fort Edward through the depths of the forest to secretly visit their father. Soon a Calvinist psalmist named David Hamut joins them - he has his own reasons to travel to Fort William Henry.
Both Alice and Cora are cautious about Magua, fearing that he has his name, The Sly Fox, for a reason. Why Magua volunteered to show them the secret path? Does he really know where do they go or they are long lost? Heyward reassures and calms down the girls until he can, but soon he starts to worry himself. Fortunately, in the evening the company of travellers meets another stranger - Hawkeye with his Indian friend Chingachgook and Chingachgook’s son Uncas. The two are the only survivors of the once great tribe of Mohican. Chingachgook agrees with the girls: the Indian who is lost in the woods in broad daylight looks strange. Moreover, Magua belongs to the Huron tribe that is unlikely to help English people at all. He offers the Major to help and interrogate Magua, but Sly Fox slips away. Now they all seem lost, but the three friends lead Duncan, Alice and Cora to the tiny rocky island to rest.
They have a modest dinner there. Uncas behaves as a real gentleman, trying to comfort Cora and Alice by all means, but it becomes obvious that he can’t help but show his affection to Cora. But despite the peaceful evening they don’t escape the danger completely. Attracted by the horses, frightened by wolves’ scent, the Hurons find their hideout. The men have to shoon and then, after they run out of ammo, engage in melee combat. The first wave of Indians is thrown away, but still the besieged company has no more ammunition to defend themselves. The only way to save themselves is to jump into the cold and fast river and swim away at night, but this task, quite plausible for Hawkeye, Indians and Duncan, is almost impossible for Cora and Alice. Cora understands it well and asks Chingachgook and Hawkeye to flee alone and bring the aid as quick as possible. Uncas is willing to stay and Cora has a great deal to convince him. If Magua was interested in them, they will be only captured, but Mohicans near them will be almost certainly killed. With a heavy heart Uncas agrees and swims away with his father. Magua (who is indeed leading the attack) reaches the island and imprisons Duncan and the girls bringing them with him.
When the Hurons stop for rest after a long march, the Sly Fox talks to Cora, opening her the real purpose of their kidnapping. It turns out that her and Alice’s father, Colonel Munro, once cruelly insulted him. To wash away this insult Cora must become his obedient wife. The girl angrily refuses despite Magua’s threats to torture her, her sister and Duncan. So, Sly Fox, insulted again, decides to cruelly execute the prisoners. All the three are tied to trees, with a wood for the bonfires under their feet. Magua asks again, reminding Cora that she also has an innocent sister, almost a child, who may die because of her being so stubborn. But Alice herself calls Magua out, saying that she prefers a painful death to hers or her sister’s humiliation.
Magua throws a tomahawk into Alice, but misses just slightly and the blade pierces the tree, nailing Alice’s hair to it. At the meantime Duncan manages to free himself from ropes and rushes to the Indians, trying to buy some more time for girls even at the price of his life. He is almost defeated, but, just before one of the Hurons delivers the final blow, a shot is heard and the Indian falls dead. Hawkeye is just in time to save the day.
After the short and bloody battle all the Hurons are defeated. But Sly Fox escapes again. He pretends to be dead and is ignored at first in the heat of the battle, but then he is nowhere to be found among the corpses.
Despite that, their dangerous travel ends safely. Hawkeye and his friends escort the three to Fort William Henry. Under the thick fog they crawl to the walls of the besieged fort and manage to get inside. The Colonel is happy to finally see his family, but is joy is overshadowed by the fact that the defenders of the fort are forced to surrender. However, the conditions of surrender are suitable and even honorable for the English side: they are allowed to keep their banners and weapons and can retreat on their own. Colonel Munro speaks to Cora, telling her that her stature and dark skin and hair are the reflection of her mother’s looks, a half-blooded Negro. Munro also secretly talks to Duncan, accusing him of racism. He thinks that Duncan ignores Cora but favours Alice because of younger sister’s fair hair and skin. But Duncan denies this saying that he is genuinely in love with Alice and do not discriminate Cora in any way.
At dawn, the garrison, burdened with wounded and weak, leaves the fort. But they can’t go fast and Magua, persistent in his hatred, tracks them down and attacks while they are at their weakest. But Sly Fox doesn’t want to kill everyone, he wreaks havoc only to kidnap the girls again and fulfil his plan. He succeeds. Cora and Alice are missing again.
The Colonel, Duncan, Chingachgook and Uncas manage to find the tracks of the kidnappers on the third day only. Uncas studies the barely noticeable signs and says that both girls are still alive and relatively well. Moreover, he is now sure that the leader of the attack is Magua again. They have no other option than to travel across the Sly Fox’s homeland, populated mostly by hostile Hurons. Losing traces and finding them again they pursue the kidnapper to the one of the Huron villages.
To their surprise, Colonel, Duncan and the Indians meet the psalmist David who is already known to them. Pretending to be a funny fool, he voluntarily followed the girls to guard and comfort them in the way he is able to. David tells them what happened: Magua decided to leave Alice for herself, sending Cora to the neighboring tribe of Delawares. Duncan, afraid of Sly Fox abusing Alice, begs Colonel to enter the village and rescue her at any costs. They agree.
Duncan puts on a disguise of another naive fool with the help of Hawkeye and Chingachgook and goes for recon. In the Huron camp he pretends to be a French healer and Indians carelessly allow him to walk around as freely as David. But suddenly Duncan sees a new captive in the village: it is Uncas. At first, he is mistaken for some random Mohican, but Magua recognizes him. The Hurons are so angry to see their sworn enemy in the middle of their own village that, had it not been the Sly Fox’s intervention, the young Uncas would be torn to pieces immediately. But Magua convinces his fellow tribesmen to postpone execution until morning, to make it especially cruel and spectacular. Uncas is locked up in a separate hut.
An old Indian, a father of the ill woman, comes to a “healer” asking for help. Duncan sees this as his chance. He orders the father to go to the cave near the village where the woman is lying, accompanied by her father and a mysterious tamed bear who seems to obey the “healer’s” wishes. Duncan enters the cave and orders everyone to go out, staying inside with the bear. But the bear isn’t real: Hawkeye is hidden under the animal costume. With the help of the hunter, Duncan finds Alice who is also hidden in the cave, but their plan is again interrupted by Magua. The Sly Fox triumphs, but not for long.
The “bear” grabs Magua and squeezes him in a deadly embrace while the Major ties his hands. But shocked and fatigued Alice can’t walk on her own. The rescue team wrap Alice in Indian clothes and Duncan carries her out, ordering the father of the real ill woman to guard the entrance to the cave to not allow the screaming “evil spirit” go out. The trick works, Duncan, Hawkeye and Alice reach the forest safely. Hawkeye shows Duncan the path leading to Delaware land, where Cora is still imprisoned, and returns to rescue Chingachgook’s son. With the help of David he deceives Uncas’ guardians and also drives them both to the forest. Duncan, understanding that the further journey will be much more dangerous than everything he did before, confesses his feelings to Alice and discovers that his affection is mutual.
Enraged Magua, who is finally found in the cave and set free, urges his tribesmen to revenge. The next morning, the Sly Fox gathers his tribe and marches to Delawares. Hiding his warriors in the forest, he enters the village just to find Uncas there. Uncas, as the last of the Mohicans and descendant of the legendary Mohican hero, demands Magua to let all the prisoners go. But Sly Fox objects that, telling the story of him being gravely offended. He is very nice, respectful and polite to the Delaware chiefs, asking them to release the prisoner. Deceived by the eloquence of the Sly Fox, the leaders agree that Cora belongs to Magua by the Indian law. Even Uncas can do nothing with it.
The Colonel offers a huge ransom for his daughter, but Magua, though he is delighted to see his enemy begging, still refuses. Uncas and others are forced to let Sly Fox go freely and take Cora with him. But the elders, who finally understand that Magua is driven by revenge only and isn’t willing to show mercy, warn him that Delawares will let him go as far as the Indian law says and then declare him their enemy and start pursuit.