It's May 23rd, Memorial Day weekend, and Promise Falls, New York, is in the midst of a full-blown catastrophe. Hundreds are hospitalized with flu-like symptoms. Dozens have died. A college student has been murdered, and Detective Barry Duckworth has seen the killer's work before. Bloody mannequins are found in car 23 of a Ferris wheel; the same number appears on a fiery, out-of-control bus and an assailant's hoodie. Working out the connection between "23" and the chaos will bring Duckworth closer to death than he's ever been before.