Thirteen year old Margaret Ann Doyle, deprived of her innocence by a shameless priest, is placed in the solitary confinement of a convent where he hides his young carnal conquests. Resisting authority at first, she finally yields to the pressures of the Abbess and dedicates her life to the Church. Over the next decade, Sister Margaret devotes her newfound talents as a nurse with the highly regarded Daughters of Charity. Responding to a need for nurses at the penal colony on the other side of the world, Sister Margaret departs for Australia. On a mission of mercy, a few years after her arrival, she is kidnapped by Bushrangers and held as their captive within the Blue Mountains of New South Wales where she establishes a clinic and treats ill and injured escaped convicts. Three years into her imprisonment, an enigmatic aborigine elder rescues her and forever changes her life. Bestowing her with mystical powers, he sends her on a religious pilgrimage to northern Mexico to meet with a young Indian, a child whose name will one day be written in the annals of Native American history. But first she must cross the path of the mighty Mexican Army on its way to oust a group of American pioneers sheltered within the walls the Alamo. On her trek across Mexico, Sister Margaret discovers a long, lost brother being held captive by the ferocious Chiricahua Indians. Using her extraordinary powers, she rescues her sibling from the Apaches and escorts him to safety in New Orleans where she almost forfeits her own life. Rescued once again by the mysterious aborigine, she boards a stern-wheeler and sails up the Mississippi River to Pittsburgh where a horse drawn packet takes her east on the Pennsylvania Canal system where river bandits rob her packet near the town of Lebanon. During the robbery, she suspects that one of the outlaws could be another long lost brother, the black sheep of the family, who had reportedly died twenty years earlier.