When a member of New York's high society is found murdered and stuffed into a small wall safe, the Department is put under pressure to get to the bottom of the story. But to get the answers to the string of robbery/murders, places must change; rather than Castle visiting New York's dark alleys, Beckett must follow him into the world of glitz, glamor, and, ultimately, murder, after they discover that the robberies are only connected by the victims having attended a specific charity event.
Detective Beckett gets rough with a witness for the first time when she shoves the table into Evan Mitchell in the interview room.
When shooting a pistol, Castle is cross-dominant (fires right handed but uses his left eye to sight the target) which occurs in only 12-15 percent of the population.
Beckett refers to Castle as "Scaramouche", then corrects his stance as he is about to shoot. Scaramouche is a roguish clown character of the Italian theater that is known for entertaining the audience with his facial expressions and language. The character can be interpreted as clever or stupid, depending on how the actor portrays him.
Based on their performance in the shooting range, Castle is actually a better shot than Beckett.
Martha quotes Anaïs Nin with, "people living deeply have no fear of death." Nin was a French-Cuban author (1903-1977) and early writer of Western erotica.
Powell mentions that his carpet is Turkish, mid-1600's, and that it was very valuable. Carpets from that region and time period often go for auction at prices exceeding a hundred thousand dollars.
Caine Powell tells Castle, "Seeing comes before wanting, Rick." Besides being a psychological fact, this is also a quote stated by Dr. Hannibal Lecter in the movie The Silence of the Lambs.
Mitchell mentions the "Glengarry leads". This is a reference to the Pulitzer Prize-winning play "Glengarry Glen Ross" by David Mamet, in which real estate salesmen are given "leads" in order to sell real estate developments.
When Castle and Beckett arrive at the party, the Mayor greets Castle with, "Why didn't you tell me you were gonna be at this shindig?" This is possibly a reference to Fillion's role in the Firefly episode "Shindig", in which Fillion's character went undercover to a fancy party.
This marks the first time when Castle's "action theme" is used. Castle sings it a cappella in Beckett's car before and after his fight scene with Nadir at the end.
During the auction, the book being auctioned off alternates from being held by Martha to being held by Rachel and back to Martha.
When Castle introduces Beckett to the Mayor at the party, the Mayor says " she's even prettier than you said " but if you watch his lips closely, you can tell that he originally said something else and the line was dubbed in. I can't tell what he originally said. Hopefully someone can read lips and let us know.