: Castle and Esposito attempt to throw an impromptu bachelor party for Ryan in Atlantic City.
: Beckett stays in New York to work with Captain Gates, while Castle, Ryan, and Esposito head to Atlantic City. It’s revealed that the casino's concierge and a security worker stole the money as leverage to help the concierge’s parents. [S4E8] Heartbreak Hotel
: Sam's ex-wife eventually confesses to the murder. She had been forced at gunpoint to sign over a co-owned building to Sam and used the theft as cover to kill him. Subplots : : Castle and Esposito attempt to throw an