|The Greater Good|
|Season 6, Episode 19|
|Air date||March 24, 2014|
|Written by||David Grae|
|Directed by||Holly Dale|
Castle and Beckett investigate the murder of a Wall Street trader, but the case takes a shocking turn when the they discover the victim was an undercover informant for the U.S. Attorney’s office. To complicate matters further, the U.S. attorney involved is Elizabeth Weston (guest star Salli Richardson-Whitfield, “Eureka”), Captain Gates’ estranged sister.
- Nathan Fillion as Richard Castle
- Stana Katic as Det. Kate Beckett
- Jon Huertas as Det. Javier Esposito
- Seamus Dever as Det. Kevin Ryan
- Tamala Jones as Dr. Lanie Parish
- Penny Johnson Jerald as Captain Victoria Gates
- Molly C. Quinn as Alexis Castle (credited only)
- Susan Sullivan as Martha Rodgers
- Salli Richardson-Whitfield as U.S. Attorney Elizabeth Weston
- Kevin Kilner as Jamie Berman
- Laurie Fortier as U.S. Attorney Stephanie Goldmark
- Ramon Fernandez as Hector Nunez
- Rosie Garcia as Maria Cordero
- Juan Carlos Cantu as Luis Delgado
- David Landry as Neal Wentworth
- Robert Maffia as Lawyer
- Andres Perez-Molina as Peter Cordero
- Noree Victoria as Secretary
- Ryan: I feel bad for Gates. My sisters could never work together. I tell you, when the two of them went at it-- Whoo!
- Esposito: I wouldn't mind going at it with Gates' sister.
- Ryan: Really? How'd you like having Gates as your sister-in-law?
- Beckett: Ryan, you guys kept your wedding small. What was it -- like 100 people?
- Ryan: Yeah, that’s all we could afford.
- Castle: How did you contain the list?
- Ryan (inhales deeply): I have a lot of relatives who hate me now.
- Castle: Of course...I'm going to have to invite my mother and Alexis.
- Beckett: Yeah, and my dad and aunt Theresa.
- Castle: Right. Espo and Ryan, who will bring Jenny.
- Beckett: Mm-hmm. Lanie.
- Castle: Lanie. I'm going to have to invite the poker group.
- Beckett: Yeah, Maddie.
- Castle: Gates.
- Beckett: Ooh! And Gates' family.
- Beckett: U.S. Attorney for the Southern District. That's a really big deal.
- Castle: Why hasn't Gates ever mentioned her before?
- Beckett: I don't know, but there was definitely a subtle chill between the two of them.
- Castle: A subtle chill? More like a polar vortex. I'm guessing something happened between them in the past. Something deeply personal that Gates does not want us to know about. I'll give you a dollar if you ask her.
- Beckett: No way.
- Casle: Come on, aren't you curious?
- Beckett: Yeah, but I like my job too much.
- Castle: We're in! Castle you've done it again.
- "El Otro Yo (The Other Me)" - Pilar Díaz
- It revealed that Gates has a sister name Elisabeth Weston who is the U.S. Attorney, which makes Weston potentially her maiden name(?) and this is also the first time we meet one of Gates' relatives.
- In this episode, Castle and Beckett start making a guest list for their upcoming wedding.
- When Castle and Beckett asked Ryan about his wedding from Till Death Do Us Part, he stated that he and Jenny had made a guest list and kept it small and simple (because that was all they could afford). As a result, he now has a lot of relatives who hate him.
- Ryan has two sisters, since he mentioned them in A Rose for Everafter and Once Upon a Crime.
- Ryan told Castle that roller coasters make him sick.
- Noree Victoria who played Secretary is Penny Johnson Jerald's sister.
- Beckett's Aunt Theresa is mentioned again when Castle suggests that she should be taken off the wedding list after having made a post that was less than flattering about Castle on her Facebook page when it was reported on page 6 that Castle had been seen canoodling with his ex-wife and publicist, Gina, in Limelight. According to Beckett, Aunt Theresa did take the post down.