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.
A murder investigation launches Castle into what seems to be an alternate universe where he's never met Kate Beckett. Castle has to convince Beckett, Esposito and Ryan—now complete strangers—to let him participate in their investigation so he can find his way back to his own world. This inspires Castle & Beckett to finally take a trip to the altar.
When Castle and Beckett wake up in bed, handcuffed together, in a locked room with no memory of how they got there, they must piece together the mystery of where they are and why, all while trying to escape. But as the two of them adjust to being shackled together, what's the biggest threat they face... the people who abducted them or each other? Meanwhile, Ryan, Esposito and Gates are left to investigate their disappearance in a case where all is not what it seems.
"In the Belly of the Beast" an undercover mission goes array putting Beckett's life in Danger.
Castle and Beckett's long-awaited wedding is almost here, but when a shocking surprise threatens to ruin the big day, they are sent on a wild mission filled with masked men, angry bikers and a charming ne'er-do-well from Beckett's past.
In "The Way of the Ninja," Castle and Beckett investigate the mysterious murder of a Japanese ballet dancer, they end up being targeted by a ninja assassin.
In "Dressed to Kill," a young woman's murder sends Castle and Beckett into the world of cutthroat world of high-end fashion.
A secret investigation conducted by Beckett related to her mother’s murder goes awry when a man she has been surveilling is killed. When evidence links Beckett to the victim, she and Castle become the targets of a manhunt that puts both of them in grave danger.
"The Greater God" — The death of a Wall Street puts the team on a collision course with Gates' sister.
When Castle and Beckett learn that a murder victim may have been poisoned at an Old West-style resort; they visit the resort—posing as newlyweds—to uncover the truth.