Although D.I.E had been dissolved and the officers returned to their previous departments, their odd habits continue to follow them, resulting in many troubles for the police force...
Richard Castle是一名著名的暢銷犯罪小說家。紐約發生了兩宗命案,刑警Kate Beckett發現作案手法與Castle的小說描述情景相同。於是她邀請Castle協助調查。Castle得知後感興趣,於是他透過與紐約市長的關係,加入Kate的命案調查中。Castle決定以Kate作為他下一本書系列女主角「Nikki Heat」的人物原形。