When the dead body of a New York City Councilman running for re-election rolls out of a rug and into Beckett's case files, she and Castle are thrown into the world of dirty politics. Meanwhile, Castle's final novel in the Derrick Storm series hits the bookstores, causing his mother to search for any and all signs of failure. And at one of his book readings, Beckett tries to throw Castle off his game, only to learn that he has flipped the script on her once again.

When an immigrant is found tortured and murdered in a ritualistic killing, Beckett navigates the uncharted territory of the mysterious Vodun religion with Castle leading the way. Having researched similar deaths for one of his books, Castle's knowledge and sources prove valuable, but only their apt teamwork can unravel the murderer's motives. Meanwhile, Castle is confronted with the possible return of his first wife, Alexis's mother, whose dizzying personality threatens to upend the tranquility of the entire family.