Jem Coulter thinks his family is just on a sightseeing trip to the big city of Sacramento. Then armed bandits hold up the stagecoach for the secret stash they’re carrying: gold for the Union Army fighting the distant Civil War! Suddenly war isn’t so far away; it’s right there on the road to Sacramento, with Jem’s father, the sheriff of Goldtown, fighting against the rebel army’s Knights of the Golden Circle.

When the family finally reaches the city, they think they’re safe at last. Setting out to see the sights, Jem, his sister Ellie, and their cousin Nathan make a new friend. But is Henry the pal they think he is? With a father who is a die-hard Confederate, could Henry be in cahoots with the thieves?