"The Final Nail" Castle and Beckett directly at odds with each other and allows us to see the understanding between them. One of Castle's old friends, Damien Westlake, from boarding school who got Castle into writing--basically starting Castle's multi-million dollar career--is suspected of murder. Castle has this idealized version of him in his head, refusing to believe Westlake could commit murder. Beckett, knowing that Castle loves and creates stories, shatters this vision, saying that Castle has created this narrative in his mind and has to see the truth. In the end, neither are entirely correct, as Westlake was not the murderer for this specific case, but he is a bad guy, revealed to have had his father killed.
While Stana Katic doesn't exactly have the range of Jennifer Beals, who delivered an incredible speech/rant in last night's episode of The Chicago Code, she does an admirable job when she confronts Castle and you could really feel the heat in the room. Afterwards, everything is fine and they go out for a drink, a friendly but not romantic gesture, which looks like the status quo for a while longer.
Score: 8.7/10