Kenny Lawson is an unfulfilled, repressed psychiatrist in Philadelphia who has been haunted by premonitions since childhood. Dreams of a little girl at play are his only nocturnal escape. One night, the girl brings him a message of death. His Hoodoo-practicing Nana reveals that the girl in his dreams is actually her sister Delilah, who disappeared in 1955. She shows him how to visit lost loved ones using "flying," a time travel method she has recently developed.
Dogged by a lifetime of relentless humiliation at the hand of his older brother, Kenny "flies" to his childhood. As a boy he had saved his only brother from a fire, but this time he let him die. This changed Kenny into the self-assured man who acquired the woman of his dreams and created a blissful life. It also changed the world around him. Nana saw it all and rebuked him.
Before Kenny can restore his old life, Nana is attacked by a foe from 1955 who has somehow discovered their time travel technique. Nana is convinced that her sister is still alive and suspects that her foe will return to look for her. She asks Kenny to join in her search for Delilah, which will take them to Jim Crow's Charleston. There, Kenny and Nana must navigate Jim Crow lynchings, vengeful curses, and the intricacies of Hoodoo magic. As they search for Delilah and try to keep villains in the past, they learn that changing the past has horrifying implications for the future.