Tom Campbell vowed to take his sister-in-law, Mary, and her two sons back to Texas if his brother died in the war. He avoided keeping his word, but public and family pressure pushes him to get horses and wagons ready to make the trip from Springfield, Missouri, to San Antonio, Texas.
Fate forces them to take a route around Kansas instead of traveling straight through Arkansas and Oklahoma. They meet the first, large cattle drive on its way to Abilene and experience the antics of crazy cowboys. With two wagons, they enter north Texas at the Caprocks and journey the barren Llano Estacado. On the howling, desolate High Plains, they get lost and run out of water. Luck steers them to the only place on the High Plains that has grass and water, the Palo Duro Canyon. Their joy soon changes to fear when Comanches spot them and attack. Tom, Mary, and the boys are miraculously saved by the actions of two cowboys who ride into help.
The trials of the journey weigh heavily on Tom. When he reflects on his life, he knows he must change, but he hopes it’s not too late.