When Jenna McBoyd, a young up-and-coming model, is found stabbed with a strange object in a fountain, Castle and Beckett are forced to explore the cutthroat world of fashion modeling. Meanwhile, Alexis reconnects with her old babysitter, and Ryan and Esposito discover an amazing secret about Beckett.
Watch for: While reviewing the murder scene, a billboard for the Metropolitan American Dance Theater is visible. MADT was the charity at the center of the string of home invasions in Home Is Where the Heart Stops.
At different points in this episode we see the issue of Cosmopolitan with the cover story on Castle. Castle's and Beckett's appearance in this magazine are based on the photo shoot and interview in "Deep in Death" and will be referenced many times after.
Castle refers to three films to illustrate a jealousy as a motive.
"The Talented Mr. Ripley" was originally a novel written by Patricia Highsmith (who wrote "Strangers on a Train" - the story that was featured prominently in The Double Down), and later made into a film (1999) in which one character becomes obsessed with another, eventually killing him and assuming his life.
"Dead Ringers" (1988) is a story of identical twins and their relationship with women.
"Showgirls" (1995), often ranked as one of the worst films ever, relates the story of a rivalry between two women seeking fame as Las Vegas showgirls.
Will James was to be charged with stalking Jenna; however, although Castle and Beckett had proven that Sierra had written the letters with him, Beckett later implies that, apart from destroying her career, Sierra will get off completely. This seems to also include her dosing Jenna with illegal drugs, also a crime.
After a bad day, Castle says that Nikki Heat would "Go home, pour a stiff drink, run a hot bath, read a good book." Beckett's date in the next episode, Fool Me Once... is exactly that.
Beckett spent a summer modeling when she was seventeen.
Alexis said she and Rina watched High School Musical together, which came out in 2006. Alexis is about 16 in this episode, which would make her about 13 when the movie came out. A bit old for needing a babysitter, but knowing how overprotective Castle is, it is not impossible.