This debut novel features a unique ghostly concept but ultimately fails to deliver. When 13-year-old Michael’s grandfather Saul dies, no one in the family grieves much. His austere manner alienated them years before. Then Michael, the narrator, “slips” out of his body into the river of the dead and discovers Saul seeking resolution to his unsatisfactory life and lonely death. Michael is drawn to Saul and wants to help him, finding obvious parallels between the older man and his own rather distant father. Classmates assist Michael as the slipping events become more frequent and harder to control: Ewan, who warns him that he can easily be trapped forever in the river of death; Gus, his former best friend; Trip, a stereotypical jock; and Michael’s sister Julia help him learn more about slipping, and pull him back from death at the climax. Insufficiently developed stock characters, a predictable conclusion and the use of dialogue to explain the complicated denouement decrease the plausibility of this tale and may make readers want to slip into something scarier. (Fiction. 10 & up)