Joined by Hiram the farmhand, Katie begins the journey west.

At first, she is unsure if the Mustang will follow, but much to her relief, he seems to trust her.

Soon, Katie and Hiram meet up with a large family who invite them to join their caravan. For the first time, it seems as though they might really make it to Oregon.

But then tragedy strikes

and Katie finds herself having to choose between parting ways with Hiram, or abandoning her dreams of going west— and giving up on the chance to return the Mustang to his homeland.