So excited to hear that Jennifer Beals is coming to Castle. What else can you tell me about the two-parter? - Eliot
ADAM: Beals plays Sophia, a CIA operative who's in town to capture a former Navy Seal who has gone rogue. (He's taken to abducting young women.) As you might expect, a bit of a turf war between the CIA and the NYPD will ensue, but that's nothing compared to the tension between Sophia and Beckett, who learn that they have a lot in common. (Think Nikki Heat.)
[SOURCE]