On a warm evening in a tranquil San Francisco, Katherine sits patiently on a hillside overlooking the Pacific Ocean. In a house on the same hill, a husband is kissing his wife goodnight for the last time. For reasons known only to Katherine, this loving husband is the focus of Katherine’s current project, and all of her projects end in the same way – death.
Meanwhile, on the other side of the country, Sebastian Giustina and his partner Basilio Machin are two of the best homicide detectives the NYPD has. Some give credit where credit is due, but others say that Sebastian has an unfair advantage that has gotten him to where he is today. Sebastian has an extremely heightened sense of smell known as hyperosmia; together with an unheard of photographic scent memory, Sebastian can detect evidence at crime scenes that would otherwise go unnoticed.
When Katherine targets a project in the great city of New York, she unwittingly leaves her victim to be found by the one detective in the world who may be able to put together the evidence and bring her serial killing to an end.