Castle and Beckett investigate the murder of a singer in a popular punk band whose body was arranged to resemble a scene in one of the band's music videos. When the case stumps the two, Alexis comes to their aid, using knowledge gained as a fan of the band.
- Aw, Look! They Really Do Love Each Other: While her first few scenes show her anger toward her sister, Sky loves Hayley, and was devastated by her death.
- Awesomeness by Analysis: While talking with one of Hayley's producers near the end of the second act, Castle walks away from the conversation to inspect the baffling in the recording studio. He noticed that one of the panels was newer than the others, prompting him to remove it and pull a piece of tape off the wall, uncovering a bullet hole from Hayley's gun. Castle and Beckett realize that Hayley and her killer were here when she was murdered, trying to defend herself.
- The Band Minus the Face: Hayley Blue's band, Blue Pill, was reduced to performing sweet sixteen parties once she went off on her own. Not only was Hayley their most talented and famous member, but she also owned the trademark for the band's name and wouldn't let the others use it.
- Broken Pedestal: Bree once saw her husband Ian as an admirable man for acting like a father figure to Hayley, and it endeared her to him further. When she learns he raped and later murdered Hayley (and was willing to let his wife take the fall for her death), she is so disgusted and horrified by what he did that she instantly files for divorce.
- Dramatic Irony: Everyone thought that Hayley was back on drugs when she disappeared a week before her death, but toxicology showed no drugs or alcohol were in her system. Castle and Alexis realize from their "Eureka!" Moment that she went missing because she was trying to expose Ian as her rapist.
- Fridge Horror: Castle and Alexis have this In-Universe when they scrutinize the lyrics to Hayley's last song, realizing that the lyrics imply something unsavory happened to her... Doubles as the epiphany that identifies the true killer and finally solves the case.Alexis: Oh, god, Dad... Does that mean what I think it means?
Castle: It means we have the wrong killer. - Know When to Fold 'Em: Sky Blue is in the morgue, yelling at Hayley's body with alcohol and knife in hand, when Beckett and Castle walk in on her. When Beckett introduces herself, Sky calmly asks if she's breaking the law right now, then hands Beckett the alcohol and knife without any further yelling.
- Likes Older Men: Ian claims this is what Hayley prefers, although that's just his version of the story and Hayley's says otherwise, but it's left up to interpretation.
- Papa Wolf: When Beckett and Castle show up to interview Hayley's former guitarist a second time, they hear a screaming match between him and Sky. While Beckett hustles a bleeding Sky off-camera and out of the scene, Castle keeps shoving the guitarist back until landing him in a chair, glaring murder the whole time.
- Punny Name: Haley's sister is named Sky Blue.
- Rape Is a Special Kind of Evil: Haley's last song is an extended description of having been assaulted. Once the context is revealed, the lyrics sound rather sinister.I closed my eyes and lived to tell.
...
I never asked, or wanted to.
You stepped across my threshold, how could you? - Screw This, I'm Outta Here: After being raped by her father figure, Hayley decided to leave her career.
- Technologically Blind Elders: Castle tells Alexis that he's going to set a new content filter on their computer to limit her exposure to tabloid information. An amused Alexis reminds him that she set up the content filter on his computer.Castle: Yeah, about that...
Alexis: No. - Tempting Fate: Played for Drama. Castle assures Alexis that the social media posts about her favorite singer's murder must be wrong; otherwise, Beckett would have called him about the case. Then his phone starts ringing, and sure enough, it's Beckett calling about the murder of Hayley Blue.
- "The Villain Sucks" Song: Hayley Blue wrote two songs ("Here Kitty Kitty" and "Threshold") insulting people who made her feel angry and uncomfortable; a Loony Fan who violated a restraining order, and the man who raped her, respectively.
- Younger Than They Look: Sky Blue is younger than her 25-year-old sister Hayley, but could pass for being in her thirties (at least in her first few scenes) due to her drug abuse.
