The `Rock Castle` is a story of the northern Mexico territory of the Wild West and incorporates the lives of German immigrants, Mormon settlers and native Indians, in a story of betrayal, greed and ultimate justice. The heroes, Old Shatterhand and Winnetou, the Apache chief, intertwine their strong morality and bravery, with the plottings and killings of renegade Indians and ruthless religious zealots trying to take possession of land and a mercury mine in the mountains of Northern Mexico. Plot after plot is brought to nothing, by the courageous frontiersmen who pursued the criminal masterminds and brought them to justice.