An immigrant wagon train is attacked by the Sioux Indians and after a hot fight all the adult white persons are killed. As the Indians sack the wagons they find a little boy and girl lying hidden in the bottom of a chest where they have been placed by their parents. According to their custom the Indians take the boy to their village to be brought up as a warrior. They tie the girl with ropes and throw her down a steep bank. She is not injured and manages to free her legs from the bonds and wander back to the burning wagons. Dick, the pet horse of the camp, has been carried away by the savages and hobbled. The wise animal unties the hobble with his teeth, returns to the scene of the massacre, sees Hattie there, and unties the ropes on her wrists. She then mounts him, rides to the nearest settlement, and is adopted by the sheriff. After 12 years with the Indians, Fred meets by chance some trappers and by them is conducted to the settlement. On telling his story it is found that he is Hattie's long-lost brother and they are again united. An exciting fight between the settlers and the Indians closes a very interesting drama.
—Moving Picture World synopsis