In 1998, Jonathan Kellerman took a brief detour from the main line of his career and published an excellent, non-series novel called Billy Straight. This month, he returns to familiar fictional territory with Monster, his 15th novel in 15 years and the 13th to feature child psychologist Alex Delaware.

In Monster, Milo Sturgis solicits Alex's help on a brutal, particularly frustrating case. Claire Argent, a 39-year-old psychologist, has been murdered, mutilated, and dumped in the trunk of her Buick Regal. There were no witnesses to the killing, and there are currently no suspects. In the months prior to her death, Claire had worked at the aptly named Starkweather Hospital for the Criminally Insane. Attempts to connect Claire's murder to her place of employment prove futile for a couple of reasons. First, her death occurred in the "outside world," beyond the reach of Starkweather's inmates. Second, her death bore striking similarities to an earlier murder, which was manifestly unconnected to Starkweather Hospital and its inhabitants.

Just as Milo and Alex turn their attention away from Starkweather, an inexplicable event takes place. Heidi Ott, a staff technician and former associate of Claire Argent's, recounts a bizarre "conversation" with imprisoned mass murderer Ardis Peake, a man who was nicknamed "Monster" by the tabloid press and who had been a particular source of interest to Claire Argent. According to Heidi Ott, Ardis, who is severely schizophrenic, has recently spoken for the first time in years, uttering cryptic phrases that seem to allude both to Claire's murder and to the subsequent murders of a pair of homeless derelicts. In the face of this questionable "evidence," Starkweather Hospital once again becomes the focus of intense police scrutiny.

Ultimately, in a manner deliberately reminiscent of classic psychoanalysis, Alex finds the answers to a complex puzzle in the distant, unresolved past. In Claire Argent's case, the past contains a traumatic secret: an act of family violence that provides essential clues to her character, her aspirations, her intense fascination with Ardis Peake, and his homicidal history. Ardis, of course, is inextricably bound to his own past, to a single night of violence in which he earned his nickname by butchering an entire family. As Alex investigates that long-forgotten massacre, he begins to discern the outline of another, hidden figure, a figure who may have played a role in those earlier killings, and who just might provide the link between past and present events. The search for that elusive figure eventually becomes the dramatic centerpiece of this intricately constructed novel.