Kellerman's third investigation for L.A. psychologist Alex Delaware begins as a densely absorbing case-history. . .but then, like its overrated predecessors (When the Bough Breaks, Blood Test), turns into an overlong, overwrought gothic, more cheap than thoughtful. Delaware is brought in as an expert-consultant for the defense--when catatonic, 18-year-old Jamey Cadmus (heir to a major fortune) is arrested, charged with complicity in a series of gay-hustler murders and the bloody demise of gay banker Digby Chancellor (who may have masterminded the serial killings). Jamey, you see, was a patient of Delaware's six years before, when he was a withdrawn, sexually confused, genius-I.Q. preteen. And ever since then Jamey has been descending into apparent schizophrenia, to the point of incoherence, paranoia, violence, and institutionalization. So Delaware examines the evidence for an insanity defense, including the instability of Jamey's parents (both dead, one a suicide). But there's a bothersome flaw in the theory--"schizophrenics don't commit serial murders"--and Delaware eventually exposes a labyrinthine but unsurprising conspiracy, featuring both "the evil doctor scenario" and "your basic extortion/elimination scenario." As long as Kellerman sticks with psycho-close-up, there's a grimly intriguing clinical narrative here, serviceably filled out with character studies of Delaware's gay-cop pal Milo, the super-competent Cadmus family lawyer, and others. Once the tacky-formula outline takes shape, however, many readers will become resentful of the long-windedness (448 p.), bored by the many anticlimactic wrap-up chapters (trapping the villain, explaining All), and increasingly irritated by the self-righteousness and purple patches that mar Dr. Delaware's sturdy narration. Still: heavy hype and a strong first half ensure a sizable audience.