During the French-Indian War, colonial scout Pathfinder becomes involved with a British sergeant's daughter and must protect her from a Tuscarora brave who wants her for himself.
Following the death of her mother, Mabel Dunham sets off to join her father in Canada. The British have just suffered a heavy defeat, by the French, at Concordia and Fort Oswego is the new front line with soldiers deserting daily.
The French Officer agrees to let Arrowhead attack Fort Oswego in two days, but suspecting a spy the British pre-empt them and attack first. Sgt. Dunham offers Hawkeye Mabel's hand in marriage, but she has taken a fancy to Jasper.
Hawkeye's marriage proposal to Mabel is turned down despite her father's blessing. Jasper takes Mabel for a trip upon the lake while aging Lt. Muir becomes more besotted. The three take part in a shooting contest to win her affections.
Jasper is suspected of being a French traitor. On the boat to Station Island he's arrested when a necklace with Arrowhead's name is found. He confesses to Mabel that Uncle Cap is leading them into a trap but saves them when attacked.
Hawkeye saves Mabel in the block house but her father dies from his wounds. Jasper helps to free them so Hawkeye offers to stand aside and let her marry him. Arrowhead still wants Mabel for his squaw but is killed by Hawkeye.
