A wagon train of pioneers is struggling westward toward Oregon through the howling winter and a band of Arikara warriors are hot on their trail. Little do the Arikaras suspect that they're about to come face-to-face and gun-to-gun with a ferocious fight they never expected, courtesy of the wily mountain man called Preacher. As Preacher struggles to bring the settlers to safety, he learns the real reason they were being attacked, and begins to suspect that the secrets they've been keeping equal a worse kind of danger.