Fans suit up to take part in the Nebula 9 fan experience at SuperNovaCon. After the simulation is over, the lights come on and the participants scream and cheer about how cool it was. As they are dismissed to put their costumes away, two fans check out the ship’s oracle pod and discover a dead body, and so begins another episode of Castle!
Castle’s at the convention, signing copies of his book, Storm Season, when Beckett moseys up to the table to grab him for the murder mystery action. Castle’s thrilled. It’s the perfect crime scene — everyone’s in a costume and can commit a murder without anyone knowing who you really are.
What Castle is less than excited about is that the victim was involved with the show Nebula 9. He would have preferred something a little less lame, say Star Trek or Battlestar Galactica. Not a show that was “canceled over a decade ago after 12 episodes, which was 12 episodes too many.” What he doesn’t know is that Beckett’s inner fangirl is screaming at him. She’s a true diehard, but keeps her composure as to not reveal her geek secret.
Beckett and Castle step onto the replicated Nebula 9 ship and meet up with Esposito and Ryan and the investigation begins. Our victim, Annabelle Collins, was the organizer for the fan experience at the convention. How she died, however, perplexes even the medical examiner (welcome back, Perlmutter!), who can’t quite figure out what weapon was used.
Enter Gabriel Winters, who played the show’s captain, Max Richards, but he’s not much help in the investigation. He’s also still very much in character and more concerned with getting the fan experience back up and running.
Meanwhile, Annabelle’s best friends Aubrey and Davis, who are downstairs running the Nebula 9 booth, are devastated. They all bonded over Nebula 9 and Annabelle even introduced Aubrey and Davis, who are now dating. They go on to explain that Annabelle cheaply bought the rights to the show and resurrected the fandom of Nebula 9 from the ashes. It wasn’t until the three of them started producing amatuer Nebula 9 websidoes, picking up where the real show left off, that the uproar and disapproval pour in, including death threats if they didn’t stop.
Castle and Beckett review the threats when Beckett runs into an old college buddy who tells Castle what a huge Nebula 9 megafan Beckett was. He has proof — a picture of Beckett dressed up as one of the show’s characters, Lieutenant Chloe. Secret’s out and Beckett’s not pleased. This only gives Castle more ammo to make fun of his girlfriend for her terrible taste in television sci-fi thrillers. But back in the ME’s office, we find out the victim’s death was caused by a burn. When asked what could have caused it, the ME says it was a high intensity laser beam. As Castle puts it, “a real sci-fi murder at a sci-fi convention.”
Esposito and Ryan aren’t having much luck interviewing convention goers about seeing Annabelle that night, until one says the she saw her go inside the fan experience with someone. That someone was Stephanie Frye, the actress who played the original Lieutenant Chloe. Annabelle had asked Stephanie to be a part of the experience, but Stephanie refused, saying that she had moved on to become a “serious” movie star actress, and the show would only be taking her backwards.
As Beckett and Castle are walking through the con, Castle spots Alexis with some of her friends, but is shocked by the skimpy costume she is wearing. Castle flips the switch into typical dad mode, but it’s Beckett who drags him away before completely embarrassing his daughter.
Beckett and Castle interrupt Winters in the middle of a performance and examine his Thorian blaster weapon. Annabelle had threatened to fire him from the experience because he was showing up late and drunk. If that was taken away from him, he wouldn’t have anything left. Castle fires the weapon and everyone is stunned that it actually burns a hole through a set piece. Bingo! The weapon has been found and things aren’t looking good for Winters.
Back at the precinct, they question Gabral. He says that he got the weapon from the props table when he was getting dressed. When asked about the possibility of being fired, Winters tells Caskett that Annabelle threatened him all the time, and she never would have actually done it. His alibi clears him. He was with two women in his hotel room that forced him to go see his doctor for some antibiotics. Ick!
Winters mentions to Caskett that Annabelle did have a boyfriend and had gotten them tickets to the show’s opening party. While Ryan and Esposito try and track him down, Castle and Beckett trace the weaponry parts back to Benjamin Donnelly, a seller of sci-fi hardware to enthusiasts. He finds out that Castle fired the gun and asks if he wore protection. Castle freaks out thinking he could start turning into a mutant at any moment. Before they leave, Donnelly tells our duo that he did sell a fully functional Thorian blaster to a man dressed in costume, driving a white SUV with North Carolina plates.
Castle heads home for the night to find Alexis waiting for him. She wanted to know if he wants to talk about the incident that happened at SuperNovaCon early that day. They both awkwardly say no and scamper off avoiding eye contact.
Ryan and Espo find the white SUV belonging to Simon Westport, Annabelle’s annual con hookup buddy. He had bought the laser as a present for Annabelle and gave it to her at the party. He had momentarily walked away and came back to find Davis trying to kiss her because he was jealous that Annabelle was all over Simon. She slapped him and left, completely upset because Davis is dating Audrey.
When Davis is questioned about the incident, he explains that it was always Annabelle that he wanted. Davis also tells them that Annabelle was gearing up to sell the rights to Nebula 9. Though they were worthless at the start, there would be talk of a movie deal and starting up the series again. If Annabelle died, the rights would go to Audrey, who indeed sold them after her BFF’s murder, for $2.5 million. Audrey explains that without Annabelle, doing the fan experience was pointless. Her alibi is a little shaky and she’s not talking after Caskett imply she killed her best friend.
Castle and Beckett head over to the Nebula 9 ship. Castle is still making fun of Beckett, who tells him to stop. She knows that the show was cheesy, but gets why people loved it so much. Even more, she says that Lieutenant Chloe symbolized everything Beckett wasn’t at the time, — independent, courageous, carefree. And with that, seeing such a vulnerable Kate, Castle happily agrees to drop the Nebula 9 jokes. Soon after, Castle runs his hand under a UV light, turning his hand green. This gives Beckett a brilliant idea of how to solve the case!
So that only leaves one person: Stephanie Frye. Frye had tried so hard to get away from the Nebula 9 image, but selling the rights to the show would have meant sucking her back in and she wasn’t going to have it. She grabs Winters’ blaster and holds it up to him, but Winters elbows her in the stomach and flips her to the ground.
Castle is worried that Beckett would be upset that her favorite character was actually the guilty party. Beckett explains that she wasn’t a fan of Frye’s, but of Lieutenant Chloe’s, and if a movie ever did come out, she would still be there to see it. Castle still hasn’t forgotten about her old Nebula 9 outfit. She agrees to put it on for him, but only if he’ll watch a Nebula 9 marathon with her. Done.
Back at Castle’s place, he begs Beckett to come out. Beckett slowly starts the big reveal, exposing one leg at a time. But then she pops out with a scary mask and a blonde wig and runs to Castle to make out. Castle screams off the bed, and locks himself in the closet, completely creeped out. Not even Castle would kiss Beckett with that face. Touche, Beckett. That’ll teach Castle to make fun of you!