The fourth installment in the beloved Detective Annalisa Vega series.

Is there such a thing as a good sociopath? Newly minted private investigator Annalisa Vega is skeptical, but her first client, Mara Delaney, insists that some sociopaths are beneficial to society. Mara has even written a book titled The Good Sociopath that is centered around Chicago neurosurgeon Craig Canning. Dr. Canning has saved hundreds of lives so it shouldn’t matter that he doesn’t actually care about his patients, should it? But Mara has a more urgent problem, which is that she is now concerned that Canning might not be such a good sociopath after all. A young woman in Canning’s apartment building mysteriously plunged to her death from a balcony, and Mara fears Canning could be responsible. She needs to uncover the truth about Canning before the book comes out, so Annalisa has little time to search for answers.

Annalisa quickly discovers that more than one person wanted the young woman dead. Canning insists he didn’t do it. His charming, unflappable demeanor suggests that either he’s telling the truth or Mara is right and he’s cold-hearted to the core. The cops, including Annalisa’s husband, think the girl’s death was an accident. The more Annalisa probes, the more she becomes convinced it’s a fiendishly clever murder, one only a brilliant psychopath could pull off. She draws deeper into a battle of wits with Canning, so determined to prove his guilt that she forgets Mara’s most important warning—that sociopaths only care about winning at all costs. When Annalisa finally peels back the layers of deceit to reveal the horrifying truth of the girl’s death, she may be too late to save herself.