Episode Description: Beware, spoilers! To read - hover over the text.
Castle and Beckett pursue a brutal killer who, they later find out is part of an international conspiracy. To investigate they are attracted to Sofia Terner — smart and attractive operating officer of the CIA, behind which a complicated past with Castle. Sofia Turner was the inspiration for castle's image of Clara Strike, a CIA agent in a series of books about Derrick Storm, a former girlfriend of the writer.