When Laurie Montgomery steps down from her position as chief medical examiner at the OCME, she and Jack decide to embark on a weekend getaway. And the timing couldn't be better when they receive a call from Jack's old peer about a strange death and their potential association with an alarming upswing in Alzheimer's cases in Essex Falls. Agreeing to help, Laurie and Jack head upstate to find that Essex Falls is far from the rural idyll of their imagination. The residents appear earnestly intent on returning America to the 1950s. They are told of the deaths of two local troublemakers, who prior to their deaths had both begun to complain of muscle spasms, nausea and off-the-charts anxiety. As Jack and Laurie investigate, they uncover a terrifying possibility: a dangerous bioweapon. In the wrong hands, it could threaten the lives of the entire town . . . and potentially all of America.