Detective Lou Bek, a Chicago homicide cop, receives a midnight call from his brother Jake, a schizophrenic whose grip on reality is controlled but fragile. When Jake takes his medication, he lives quietly at home with their mother, entertaining himself with “Star Trek” reruns and visits to Chicago’s Adler Planetarium. When Jake forgets the drugs, the panicky, often violent symptoms of his affliction take over. Lou answers the phone that night to hear Jake muttering almost incoherently at the other end about a monster he calls “the Whistler” – and about a dead body at the planetarium. Lou believes his worst nightmare has come to life when he goes to the museum, finds the body of a woman who’s been raped and strangled, and returns home to find Jake covered with blood. In the murder investigation that follows, Lou must decide if Jake was killer or witness in a race for the crime’s solution against the outraged brother of the victim and Lou’s own partner, Detective Susan Mackie. Not to mention the Whistler himself…