After leaving a life of unhappy privilege in India to settle his younger brother's financial crisis in England, Clayton is held in thrall by an insatiable courtesan with tendencies to drink blood. Against his will she turns him into a vampire. Anger, dismay, and remorse shape his life as he tries to cope with his unwanted vampiric nature and the constant need for blood. After twenty-odd years in England, Clayton leaves for a new life and opportunity in America. The passenger ship encounters a hurricane and is forced to land in Cuba where he is approached by a mysterious bruja crone and given an elixir that will, if taken daily for one year, allow him to walk in the sun as a Day Walker. The elixir is successful, and he remains in Cuba for several years before finally resuming his journey to America.
He becomes a successful restaurant owner in Charleston, South Carolina when his life is changed once more with an unusually strong and lustful response to meeting sixteen-year-old Mary Ellington. Four years later, he meets Mary again and falls deeply in love with her despite his dread that his blood lust might cause her death. Their brief love affair and his proposal of marriage ends with an assassin's bullet on the eve of America' s Civil War. His injuries are severe and cause Clayton to lose all memories of Mary but during the war, images of a weeping woman drenched in blood and whispering his name continue to haunt his dreams.
After returning to civilian life, he feels a strong urge to head west, still not realizing, he and Mary had often spoken of ranch life together after the war.
Mary thinks Clayton is dead even though his body disappeared the night of the murder. After the war is over and Mary has come to terms with being alone, she decides to move to Colorado and run the ranch left to her in her aunt's will. Years later, exhausted by the continued harassment of persons unknown, she decides to sell her beloved ranch, but only to the right buyer.
The lovers, separated by time and distance, continue to be drawn together as Clayton moves west towards Mary, whom he's never met and their love he doesn't remember.