An eight-month pregnant woman visits a gypsy fortune teller at a summer carnival in 1943. The fortune teller looks into the woman’s eyes and says the woman has a troubled soul. The gypsy also says that the woman has a “dark cloud” in her life that must be discarded if she and the baby in her womb are to have happy lives. The woman asks about the baby and is told that it is a boy and that the boy will be able to do something better than anyone else in the world. Five years later the gypsy offers a similar, but complementary prediction to another pregnant woman, and the stage is set for an epic battle between good and evil on the baseball diamond.

The book focuses primarily on the development of Billy Diamond from a Little League sensation to a Major League relief pitching icon. Although Billy’s mother is successful initially in ridding herself of the dark cloud and makes a wonderful life for herself and Billy, the dark cloud remains a threat to their happiness. In the end, Billy must decide whether to comply with the nefarious demands of the dark cloud or use all of his magical assets to do what he does best on the baseball diamond…throw an incredible fastball. The future of his family hangs in the balance.