Dr. Laszlo Kreizler, alienist (as psychiatrists were known 100 years ago), is back in this sequel to Caleb Carr's The Alienist (1). In the previous novel, Dr. Kreizler was called on by police commissioner Theodore Roosevelt to use not only his skills as an alienist but also his knowledge of forensic psychiatry to solve a series of brutal murders of young boys. He knew he must get inside the mind of the murderer if the case was to be solved. To help him, he assembled a rag-tag team that included two detectives who specialized in the new field of forensics, a crime reporter, and Kreizler's own personal assistant, plus a young street urchin he was trying to rehabilitate and Roosevelt's secretary, Sara Howard.

In The Angel of Darkness, it is one year later, 1897. Sara Howard, who is now running her own detective agency, calls on Dr. Kreizler and his investigative team to help her solve the kidnapping of the young daughter of a Spanish diplomat. Time is running out, not only for missing baby Anna but also for the political forces led by Theodore Roosevelt, who are agitating for war with Spain.

The investigation quickly moves from the crime-infested streets of lower Manhattan to the gambling casinos of Saratoga Springs, New York, and into the small towns of upstate New York, where Sara Howard and her team follow the trail of Libby Hatch, a child-nurse and mother they suspect is the kidnapper. Kreizler uncovers evidence that Mrs. Hatch may be a child murderer. But what in her past could have driven her to such violent and unnatural acts?

While seeking answers to these questions, Kreizler and his cohorts confront the more basic question of the nature of woman. Is she a nurturer and born mother, as William James asserts? Is she granted, by divine right, the ability to love and procreate, a force of nature so powerful that it can be thwarted only by the violence of men, as stated by Elizabeth Cady Stanton? Is any alienist of the time, most of whom are men, even capable of understanding the true nature of women?

If Mrs. Hatch is a child-murderer, what could have turned her into such an "unnatural" woman? The answer to this question must be found, and it must be convincing enough to persuade a jury of Mrs. Hatch's peers that not all females are born nurturers who are incapable of infanticide. Moreover, the answer must be found soon. Otherwise little Anna may well be the murderess's next victim.

Carr once again skillfully mixes historical figures with fiction. Clarence Darrow is brought in to defend Libby Hatch. Will he win an acquittal? What part will Roosevelt and his warmongering friends play in the drama? The Angel of Darkness is a suspenseful and psychologically insightful mystery that rewards readers not so much with absolute answers as with provocative questions about the nature of womanhood and the role of women in society.

Ms. Packer-Fletcher is a freelance writer, and Dr. Fletcher is assistant professor of psychiatry and director of the behavioral sciences research core in the department of psychiatry at the University of Massachusetts Medical Center in Worcester.