Jem Coulter and his friends celebrate the end of the Civil War in their town with firecrackers, parades, and anticipation for a bear-and-bull fight. But chaos ensues when a bull breaks loose, causing wood splinters and fence posts to rain down and break his cousin Nathan's legs. With the Coulter family unable to afford a San Francisco surgeon, the family and their friend Strike-It-Rich Sam devise a plan to raise money. Jem, his sister Ellie, and Strike embark on a quest to recover lost gold. Will they find their treasure in the valley, or will they have to strike more gold in order to help Nathan?