The prologue of veteran horror writer Saul's ( Second Child ) new novel is wonderfully scary: A pregnant teenage "swamp rat" of the Everglades, spying on a secret meeting of "the Dark Man" and "his children," sees a friend offer up her newborn baby, whereupon the masked Dark Man plunges a knife into the infant. Right after that, the teenager's husband promises to deliver his own child "the night he's born." The story proper begins when 16-year-old Kelly Anderson, all her life having suffered nightmares of a menacing old man and now sure she's pregnant by him, tries to kill herself. She recovers and moves from Atlanta with her adoptive parents to her grandfather's house just north of the Everglades. Kelly becomes friends with Michael, her age and also adopted, who admits to similar nightmares and a sense of dread. Michael's adoptive mother, meanwhile, feels a strange kinship to Kelly. The secrets of the Dark Man--his identity and his fountain-of-youth formula--are revealed halfway through the book, and thenceforth the story slides into descriptions of relatively tame to-and-fro-ing, mostly in the swamp, and the revolting revenge of "the children" on a group of nasty but well-preserved old men. Saul's ending is cozily sentimental.