Regina Cane isn't happy that Josie Lange is at her album release party. She also isn't thrilled when Castle and Beckett awaken her the next morning with questions about the murder of Holly Rhodes, aka DJ Beat, who was cranking the tunes at her bash. As it turns out, Holly skipped out of the party and never returned. Lanie determines that the victim was killed near a Chinese restaurant. Synthetic fibers were also found on her clothes.
Tyrese Wilton is a record producer who works with Josie Lange and used to represent Regina Cane back in the day. He met Holly at the party and wanted to take her to the next level. Tyrese says the victim had a confrontation with rapper MC Thug. The guy had threatened her in the past over a bracelet that was stolen by either her or her assistant at a prior party. There were thefts at many of the events Holly worked.
Items were stolen at the gigs where Holly worked with someone who wasn't her regular assistant. This person was seen wearing a hoodie at Regina Cane's party. Joey Malone, street name Monster, is indentified at the assistant in question. He's a 14-year-old kid who has led a rough life. He gets visibly upset when Beckett accuses him of killing Holly. He also alibis out for the murder.
Esposito believes there's a mastermind behind the thefts, but Joey is loyal to whoever is pulling his strings. This makes the kid a loose end for the killer. Esposito offers to take him back to his place to keep him safe. These two seem to be getting along right up until the moment Joey skips out the window. The kid's wily, but Espo is wilier. He wrangles up the kid, who still isn't talking.
The team realizes a lowlife named Shane Winters preys on troubled teens like Joey. His car matches the kind that holds the fibers that were found on the victim's body. Esposito brings in Shane after persuading his bodyguard to step aside with a swift kick to the groin. Shane denies killing Holly and says that his car accidentally went up in flames. That means they can't match the fibers to connect him to the crime.
Esposito plays Joey a video of the interrogation to show how Shane is willing to pin the crime on him. This has the kid revealing that his last job was a little odd. He was only to steal a cell phone belonging to Tyrese Wilton. Holly flipped out when she found out about this. That was last time Joey saw her. As for Shane, he has an airtight alibi. Castle wonders why the phone was stolen. It could be the key to the case.
There's a Chinese restaurant in the alley where Tyrese Wilton's studio is located. The producer says his cell phone was missing for awhile, but it turned up later at the party. He realizes that during the time the phone was gone, someone used it as an E-Key to break in to his studio. They downloaded Josie Lang's yet-to-be-released album. Castle realizes it had to have been someone at the party. But who would have something to gain from downloading Josie Lang's album?
Castle and Beckett realize that Regina Cane was MIA during the time of the murder. The aging star's album sales have been sagging for years. She intended to leak Josie's album online to hurt her sales. Unfortunately, Holly showed up at the studio to stop her. The two fought and Regina killed Holly. She called Shane Winters to help dump the body. Case closed.
Esposito pays a visit to Shane Winters, who is walking away from charges of grand larceny and accessory after-the-fact due to lack of evidence. He's also being asked to walk away from Joey forever. Esposito shows him two guns. One of them is the one he'll say Shane pulled on him. The other is the one he'll use to shoot Shane in self-defense. The lowlife gets the message. As for Joey, Esposito offers to help him to get back on the right path. The kid has heard this type of thing before, but this time he's hearing it from someone who means it.