NORTHWEST PASSAGE

In 1759, Langdon Towne, son of a ropemaker and ship rigger, returns to Portsmouth, New Hampshire, after his expulsion from Harvard University. Although disappointed, his family greets him with love, as does Elizabeth Browne. Elizabeth's father, a noted clergyman, is less welcoming and denigrates Langdon's aspirations to become a painter.

At the local tavern with friend Sam Livermore, Langdon disparages Wiseman Clagett, the king's attorney and the Native American agent Sir William Johnson, unaware that Clagett is in the next room with another official. Facing arrest, Langdon fights the two men with the help of "Hunk" Marriner, a local woodsman and both escape into the countryside.

Fleeing westward, Langdon and Marriner stop in a backwoods tavern, where they help a man in a green uniform. After a night of drinking "Flip" (similar to hot buttered rum), the two men wake up at Fort Crown Point, where they learn the man they met is Major Robert Rogers, commander of Rogers' Rangers. In need of Langdon's map-making skills, Rogers recruits the two men for his latest expedition to destroy the hostile Abenakis tribe and their town of St. Francis, far to the north.

Rogers's force rows north in whale boats on Lake Champlain by night, evading French patrols, but several soldiers are injured in a confrontation with Mohawk scouts. Rogers sends not only the wounded back to Crown Point, but also the disloyal Mohawks provided by Sir William Johnson and a number of men who disobeyed orders. Concealing their boats, the depleted force marches through swampland to conceal their movements. Informed by Stockbridge Indian scouts that the French have captured their boats and extra supplies, Rogers revises his plan and sends an injured officer back to Fort Crown Point requesting the British send supplies to old Fort Wentworth, to be met by the returning rangers.

Making a human chain to cross a river, the rangers reach St. Francis. Their attack succeeds, and they set fire to the dwellings and cut the Abenakis off from retreat. After the battle, the rangers find only a few baskets of parched corn to replenish their provisions. Marriner finds Langdon shot in his abdomen. The rangers set out for Wentworth, pursued by hostile French and Indian forces. Their initial objective is Lake Memphremagog, with the injured Langdon bringing up the rear.

Ten days later, Rogers's men reach the hills above Lake Memphremagog. Encountering signs of French activity, Rogers prefers to press on a hundred miles to Fort Wentworth, but the men vote to split up into four parties to hunt for food. Game proves scarce and two of the detachments are ambushed by the French, leaving most of the men dead. Persevering through harsh conditions, Rogers and the remaining fifty men finally reach the fort, only to find it unoccupied and in disrepair, and the British relief column has not arrived. Though personally despairing, Rogers attempts to perk up their flagging spirits with a prayer. They then hear the fifes and drums of approaching British boats with the supplies. Reporting that the Abenakis have been destroyed, the British honour Rogers' men by presenting their firearms and shouting "Hip, hip, hooray".

Returning to Portsmouth, Langdon reunites with Elizabeth while the Rangers are given a new mission: to find the Northwest Passage. Rogers fires them up with a speech about the wonders they will see on the march to the first point of embarkation, a little fort called "Detroit". He passes by Langdon and Elizabeth to say goodbye; Elizabeth informs him that she and Langdon are headed for London, where she is hopeful Langdon will become a great painter. Rogers bids them farewell, and marches down the road, into the sunset.

Rogers and the surviving Rangers finally reach Fort Wentworth after a perilous journey, only to find the fort empty of soldiers and the vital supplies they desperately need.

The ending underscores the relentless hardship faced by the Rangers, emphasizing survival against overwhelming odds and nature's indifference. The film closes on a note of resilience and tragedy, as the promise of refuge turns into yet another trial, highlighting the stark realities of frontier warfare and the cost of ambition and loyalty.