When Army scout and mountain man, Zeb Macahan (James Arness) comes home to Virginia after being away for ten years, his family is worried by talk of the imminent United States Civil War. Zeb's brother Timothy (Richard Kiley) and Timothy's wife, Kate (Eva Marie Saint), decide to move west.

Luke is shot trying to keep residents of an Indian village from being massacred.

A religious sect cares for wounded Luke while he avoids a bounty hunter; a gunfighter courts Kate.

Zeb leads Cully's son to safety and returns to the Arikara Indian camp to fire a merciful bullet, killing Cully instantly. While the Macahan family is under attack by hostile Indians, Erika joins Luke on the trail.

Zeb must solve problems between the Indians and a Russian who wants to experience a buffalo hunt.

A Russian dies after a treaty is violated; a polygamist proposes to Laura.