When Indians attack her home in Missouri, Cassandra Black's life appears utterly destroyed. Orphaned and homeless, she moves to Cheyenne, Wyoming, to live with her childless Uncle George and Aunt Mabel. Finding a safe home on the cattle ranch owned by her kind and hardworking relatives, Cassie gets to know the tight-knit community of the railroad town. In letters to her friend Madeline, she writes about her budding feelings for the handsome, somewhat solitary Sherriff Edward Havoc. This relationship is only complicated when Cassie realizes that the Indian attack has left her pregnant and fears the repercussions of revealing this to her potential spouse. Both Ed and her family are surprisingly accepting of her misfortune, and when he makes an official proposal of marriage to her uncle, this is accepted with glee by all parties. With Cassie, Ed finally sees an opportunity to retire as sheriff and realize his dream of starting his own cattle ranch. A final threat to her bliss comes when Cassie is woken by a knock on the door. The Indian family on her doorstep initially fills her with fear, but she manages to overcome her trauma and invites them in. Despite her efforts, the woman dies giving birth to a stillborn, and Cassie and Ed promise to take care of Luka, the family's little boy, while the man leaves to bury his wife and stillborn child. With the birth of her baby girl, Cassie and Edward's family is complete, and they finally find their happily ever after.