Mary Clare Ryan, a brilliant young Washington, D.C., research biologist is killed in a car crash that her sister Nicole, an associate professor of mythology and comparative religion, isn't convinced was an accident. A plane ticket to Los Angeles originally in Mary Clare's name is mysteriously signed over and sent to Nikki, who also finds a photo of her sister with documentary filmmaker Dan Rossi, the man Nikki had been seeing before he abruptly left for L.A. three months earlier. A notebook that Mary Clare had asked Nikki to give to Dan "if anything ever happens to me" is now missing. Nikki flies to L.A., where Mary Clare was to have attended an immunology conference, and stays at Dan's place in order to snoop. Nikki becomes convinced that Mary Clare, who had discovered the key to a revolutionary new drug, was murdered. After persuading L.A. detective sergeant Leo De Santo that something odd is going on, she and he pool resources to find Mary Clare's killer. Folk tales and abusive relationships are additional elements in this fairly predictable tale.
My favorite of O'Brien's mysteries!