At first it all seemed like just evil hooliganism - carcasses of squirrels hung on fences, mannequins smeared with red paint in the cabin of a Ferris wheel, the hijacking and burning of a bus... And then - instead of paint and animal blood, human blood began to be shed in the town of Promise Falls .An explosion in an open-air cinema...The body of a local college student with signs of violent death...And finally - hundreds of townspeople who suffered from an unknown poisoning. What does the mysterious criminal want? Who is he? How to catch him? Police officer Barry Duckworth and private detective Cal Weaver begin a joint hunt for the killer. But so far the only connection between his crimes and their only clue is the mysterious number “23”, with which the maniac meticulously marks each of his actions...