From New York Times and #1 international bestselling author Linwood Barclay comes the jaw-dropping finale of the Promise Falls Trilogy. It’s May 23, and small town Promise Falls finds itself in the midst of a full-blown catastrophe with dozens dead from a flu-like virus. Investigator Cal Weaver quickly zeros in on mass poisoning and a tainted water supply. Meanwhile, a college student has been murdered, and Detective Barry Duckworth recognizes a killer’s handiwork from the…