It’s May 23rd, and the small town of Promise Falls, New York, has found itself in the midst of a full-blown catastrophe. Hundreds of people are going to the hospital with similar flu-like symptoms, and dozens have died. Investigators quickly zero in on the water supply. But the question for many, including private investigator Cal Weaver, remains: Who would benefit from a mass poisoning of this town? Meanwhile, a college student has been murdered, and Detective Barry Duckworth has seen the killer’s handiwork before --- in the unsolved homicides of two other women in town. Suddenly, all the strange things that have happened in the last month start to add up.