In this less than suspenseful supernatural thriller from Koontz (Breathless), 14-year-old Billy Lucas's inexplicable slaughter of his entire family awakens the fears of homicide detective John Calvino, who as a child was the sole survivor of a similar family massacre. Though Calvino slayed the fiend who did the deed, he has always worried that the killings were demonic in nature and that the evil spirit responsible would return and harm his wife and three children. Sure enough, after Calvino visits the psychiatric ward where Lucas is held, something starts to haunt every member of his close-knit clan, though improbably and conveniently they all fail to share this disturbing development with each other. The detective believes he has a deadline to thwart the force bent on repeating the earlier murders. The terror level never reaches that of similarly themed works such as the movie Fallen. Clunky prose (e.g., Andy Tane, a cop, "is figuratively and literally a horse") doesn't help.