Amber Middlebury was strangled with her own sash. A piece of sequins is found in her hair. Business mogul Victor Baron (guest star Michael McKean) and his lovely wife, Kayla (guest star Teri Polo), are devastated by the death of one of their own. Well, they're devastated while the cameras are rolling. Victor tells Beckett that pageant coordinator Candace Ford will give her anything she needs for her investigation.
One of contestants heard Amber arguing with a man shortly before she was killed. It may have been an angry boyfriend. Amber's consultant, Justin Hankel, knows nothing about this. He does, however, say his client claimed someone was trying to take advantage of her. Perhaps it was the pageant's host, Bobby Stark, as he wore the tux that bore the piece of sequins that was found.
[break] Three women have filed restraining orders against Stark in the past. But the guy alibis out. Miss Georgia thinks she knows why Miss Illinois was murdered. She discovered naked photos of Amber with a blackmail note attached on the back. A photographer from Amber's past says her boyfriend, Jeremy, fancied himself an amateur shutterbug. But the boyfriend's not a suspect, as someone murdered Jeremy before Amber was killed.
On the home front, Alexis wants Ashley to go off to Stanford. It's always been his dream. She knows the odds of a long distance relationship working out are not great. That's why she does the practical thing by breaking up with him. After receiving a visit from Ashley, Castle has a heart-to-heart with Alexis. He encourages her to look at the big picture of this situation. Speaking of pictures…
Castle realizes the naked photos of victim were shot at Victor Baron's house in the Hamptons. But Baron says he wasn't blackmailing Amber. Actually, she was blackmailing him with pictures her boyfriend shot at his place. The photos would ruin him, so Victor Baron agreed to help her win the pageant. An angry Kayla verifies that Victor was with him at the time of the murder.
[break] The only other person who knew about the blackmail was pageant coordinator Candace Ford. But she alibis out, as she was with Bobby Stark at the time of the murder. Eventually, Castle and Beckett realize that Justin Hankel has been lying to them. He knew about the blackmail, confronted Amber's boyfriend and killed him. When he realized Amber was in on the scheme, he had to get rid of her, too. Case closed.
In other news, Captain Montgomery has been stressing about what to get his wife for their 30th wedding anniversary. Castle says, "The best thing to give a woman is something she said she wanted when she didn't think you were listening." So, Montgomery gives the gift of himself by announcing his retirement. Castle is stunned until Beckett clues him in. Apparently, Captain Montgomery retires all the time. It never takes. According to Beckett, the big boss isn't going anywhere.
Ashley, however, is still headed for Stanford. That's the good news. The bad news is that Alexis is going with him. For a guy who weaves tales of mystery for a living, this is one plot twist Castle never saw coming.