Diehl expertly juggles three murder investigations in a high-octane legal thriller, his follow-up to Primal Fear (1992). Martin Vail is back, still a hotshot lawyer with a big mouth, though he's given up being a defense attorney to take the number-two position in the Chicago DA's office. Vail and his team of young, aggressive lawyers take on a man they're sure has murdered his wife, in spite of a very tight self-defense alibi. Meanwhile, the local Democratic Party boss is slain, and the prime suspect is all too willing to admit her guilt, until Jane Venable -- Vail's former opponent and now his lover -- takes up the defense. Interwoven with these investigations is the meat of the novel: a series of psychopathic killings. Clues abound, including a code written in blood on each victim's skull. But all the evidence points to Aaron Stampler -- who has been locked in a maximum-security mental institution for the last decade. Vail defended Stampler in Primal Fear and plea-bargained him (via a multiple-personality disorder) into a psychiatric hospital to avoid the death penalty. Now, Vail is convinced that Stampler's multiple personalities are a hoax. His psychiatrist, though, judges the inmate cured and releases him -- allowing Stampler to go after everyone who helped put him away. While developments after Stampler's release can be predictable, Diehl usually keeps readers off-balance and wondering. But the hero-worship shtick Vail's associates direct at him gets embarrassing -- especially after the twelfth time. Will score no points with the mental-health community, which looks smug, stupid and flat-out dangerous thanks to one Dr. Woodward, but a tense and often scary read for the rest of us.