Synopsis

Castle and Beckett are in a desperate race against time to locate the "Linchpin"—the single element that will trigger a cascade of events leading the United States into war. Their pursuit draws Castle into contact with Sophia Conrad, a sharp, assertive, and strikingly attractive CIA operative. She is the very inspiration for Clara Strike, Castle’s fictional creation from the “Derrick Storm” novels. And adding to the complexity, intelligence officer Martin Danberg has returned.