A stagecoach rattles its way across the Mogollon Plateau, carrying a cargo of gold bullion. Passenger Lucy Calendar, the new schoolteacher at Casa Grande, is fearful of being attacked by Dutch Henry Vandyke and his gang, and must trust in the mounted bluecoats escorting the vehicle. But the soldiers are relieved by strangers at Sedona - and when the coach is held up further along the trail, Lucy finds that not only has the Vandyke Gang infiltrated the escort, but Dutch Henry himself has been riding in the coach all along ...