The heroine of the novel, a prosecutor’s investigator, investigates a series of sudden suicides of quite well-off, cheerful people. Gradually she comes to the conclusion that she is dealing with some kind of self-styled intellectual deity or demon—who, to maintain his own stability, needs systematic bloody sacrifices, much like ancient bloodthirsty gods who required victims. Using any leads, acting sometimes almost blindly, and relying on help from a wide variety of people—from psychics to computer geniuses—the heroine of the novel develops, on the go, a strategy and tactics for fighting the incomprehensible and bloodthirsty foe.