A fictionalized account of the real-life adventures of the Sager family. Travelling with a wagon train from Missouri to Oregon, things are going well for them, until Henry dies from blood poisoning following an Indian attack, and Naomi dies soon afterward from pneumonia. The leaders of the wagon train decide to send the children back to Missouri, but the oldest, John (who had been described by all the adults as lazy and worthless), decides to lead his siblings through the wilderness to complete the journey their parents started.