Castle hasn't exactly completed the letter of recommendation Pi asked him to whip up for a grant application. Okay, he's hasn't written a word. Castle flips open the laptop to embark on this impossible endeavor when the best possible news comes in. There's been a murder!
Pop diva Mandy Sutton is dead at the young age of 22. She was found in the alley of her apartment building. Her mother and personal assistant say there were many who disapproved on Mandy's lifestyle. She'd been partying pretty hard the last few days. Her boyfriend, Zach, broke up with her after tabloids caught her kissing another guy. It was her ex, Jesse Jones, who has priors. But the guy alibis out. He didn't kill Mandy. Actually, no one did. The victim is actually a woman named Claire Samuels. She was an aspiring actress who worked as Mandy's decoy for the paparazzi. There's a chance the pop diva was the real target.
Castle and Beckett find Mandy passed out drunk in a hotel room. The celeb has no idea why Claire would have been at her apartment the night before. She's a little hazy on the details of the past few days. A threatening fan letter included photos of Mandy in her bedroom while she was sleeping. Castle calms the pop star down with some coffee. He can relate to the pressure of being a celebrity on a smaller scale as evidenced by the fact that Mandy doesn't even know who he is. Alexis sure knows Mandy though, as evidenced by the fact that she inadvertently refers to her as a hot mess right to her face. Oops.
Alexis accidentally switches phones with Mandy. She heads over to her hotel to make an exchange. She apologizes for the whole "hot mess" comment. Mandy reveals that she truly regrets losing Zach. She wishes she could disappear from her life. Surprisingly, Alexis feels the same way. She feels she made a huge mistake by moving in with Pi. Their conversation is interrupted when Mandy gets a text from her friend Sam. Odd since she's supposed to be dead. Anyway, Sam claims to have info on the real victim. Alexis tags along as Mandy heads off to meet this guy at the club where he works.
As the team continues to work the case, they learn that the victim ordered a limo to take her to Mandy's place. An obsessed fan saw a motorcycle going into the alley around the time of the murder. It belongs to Jesse Jones. They need to find Mandy before the guy before he realizes she's alive. At the club, Alexis and Mandy learn that Claire was there the night she was killed. The victim had a conversation with Jesse that left her very upset. Mandy is eventually recognized by fans. Word quickly spreads that she's very much alive.
Castle sees Alexis on the news as she and Mandy flee the club. Jesse shows up outside. He orders Mandy and Alexis into his truck. He wants to know who is messing with him as he pulls out a gun. Someone paid him to kiss Claire for the photo that caused such a firestorm. The decoy was in on the scam, but wanted to come clean. Mandy was so out of it, she never even knew that she wasn't unfaithful to her boyfriend. Alexis believes that perhaps Mandy was drugged. Jesse swears Claire was dead when he got there. Perhaps she was the intended target after all.
Harvey Stryker from Celebgazer.com tipped off the photographer which means he may have set the whole thing up. His business was hurting ever since Mandy turned her life around with Zach. Stryker says he was tipped about Claire and Jesse being at the bar by someone who used a burner phone. Whoever bought it is the killer. Mandy is shocked to learn that the person who set all this up was her manager, aka her mother. She was upset because Zach was going to take her away from the life that was making them millions. Case closed.
Castle tells Mandy that it would be really easy for her to run and hide after all that's happened. He advises her to not do that. This advice will be a bit easier to take since Alexis took it upon herself to reunite Zach with Mandy. She still has to deal with her own relationship though. Speaking of relationships, Beckett finally reveals hers to Castle publically with her engagement announcement in the paper. Sadly, it makes no mention of Castle's desired wedding in space.