The scene opens with Castle, who is dressed as Elvis, getting dragged into an office. The man tells Castle that he told him not go come already. The scene flashbacks to 16 hours earlier where Castle comes into the living room to find Alexis in her pajamas. He asks why she is not at school and she says that they have a free day and that she doesn’t want to get dressed. He asks how she is doing and Alexis starts to think that it was a bad idea to break up with Ashley. He suggests that Alexis invite some girls over and they have a girl’s night. Beckett calls up Castle and he goes out to meet her. Beckett says that the victim is Sam Siegal, part owner of the Sapphire Club Casino. Lanie says that Sam was killed by a small caliber to the chest at close range. Esposito and Ryan get on the scene and Esposito says that Sam was carrying a gun too. Esposito tries to make a joke and Lanie chastises him. He asks what he did and Castle says that he broke up with her. Beckett tells him that she is staying out of it.
Beckett tells Ryan and Esposito to go check out the Sapphire. Castle says that Atlantic City is perfect for the Bachelor Party. However, Ryan says that they can go camping instead. Esposito says that he doesn’t have that say and says that it is Best Man’s territory. When Esposito asks how they are going choose the Best Man, Ryan runs off. Beckett finds out the last known address to where Sam went before to the place where he got shot. She finds an address. They go back to the station and Esposito says that Sam was a real estate agent who made it big and then went to the way of Casinos instead. He says that Sam had a foundation that gives money to underprivileged schools. Beckett says that they need to go to the casino and talk to the staff. Ryan says that the address that they found on the GPS belongs to Sam’s ex-wife, Rebecca. He says that there was an argument reported. Beckett brings in Rebecca and she says that she didn’t kill Sam over an argument about signing over the property over to him. He offered $1.5 Million, but she refused. She says that she thought that he was working an angle.
Beckett tells everyone that Rebecca’s alibi is solid and says the doorman said that she was in her place the entire time. Capt. Gates comes out and tells Beckett that the Mayor of Atlantic City called and said that the murder is front page news. Castle tries to give some detail, but the look that Gates gives shuts him down. Ryan comes in and says that Sam wasn’t alone. He says that Sam had a driver named Ralph Marino, a man with a record. Gates tells the guys to go to Atlantic City and tells Beckett that she is going to work in New York to see what she can find. Beckett calls for Castle to join her, but Gates intervenes and tells Castle to go with Esposito and Ryan. Gates tells Beckett that she is excited to see what she could do without Castle. Just as the guys are leaving, Castle says that he is with them on this one. In the car, Castle calls Alexis and tells her that he is going to Atlantic City and says that he might be staying overnight. Ryan says that they are not going to stay overnight and Esposito says that they have to scope it out for potential Bachelor Party venues. However, Ryan says that he had to pick Jenny’s half-brother Nelson to be the Best Man. Esposito is upset and Castle tries to tell him that Ryan had no choice, but he is still upset. He says that he was going to give him a good send-off. Castle suggests that they have an Impromptu Bachelor Party while they are on case.
They get to the casino and meet Nadine, the personal concierge. They ask for Charlie Turner, the casino’s owner and she offers to take them to his table. Castle asks who is playing tonight and she says that they are hosting an Elvis impersonation contest so only Carrot Top. Castle is happy that they came. Back in New York, Gates tells Beckett that she is not being punished. She just wants to see how well she works without “distractions”. Castle, Ryan and Esposito meet with Turner and he says that he Sam hated the city. They ask about Ralph Marino and Turner says that he is surprised that Ralph was still driving for Sam after what happened. Daniel Sullivan, the tech guy of the casino, comes up and says that they have a card counter in the casino and Castle says that it seems like they run a tight ship there at the casino. Esposito asks why Ralph and Sam were mad at one another. Turner says that Sam asks Ralph’s girlfriend to “blow on his dice”. Turner says that Sam was on a hot streak, but his luck changed. Meanwhile, Beckett goes to the home of Ralph Marino’s cousin and finds him there.
She takes him in and he says that he didn’t kill anyone, but ran because he knew that they suspected him of doing it. He says that he didn’t see who Sam was meeting with earlier that day and says that it was heated. Beckett tells Gates that Ralph didn’t have a reason to want Sam dead. She tries to look at the timeline and asks herself what is so special about the property that Sam wanted solely in his name. In Atlantic City, Castle gets 3 tickets to a Burlesque Show. They talk about what Sam did to get a bloody lip. Castle asks how the property is connected and Ryan says that they have to find out who threw the punch. Castle says that he knows how to get that information. They go to Daniel. He pulls up the footage of Sam and Castle asks if they have anything on him. He pulls up that Castle lit a mattress on fire and covered the curtains with jam. Castle laughs and says that it was a fun night. They watch the footage that Sam is in and find that he had the bloody lip at 2:00 and Esposito says for Daniel to back up the footage. In New York, Beckett comes into Gate’s office and says that Sam whipped out $10 Million out of the casino account. In Atlantic City, they find out that it was Turner who threw the punch at Sam. Esposito gets off the phone with Beckett and tells Ryan and Castle that Sam ripped off the casino.
They talk to Turner again and he says that he knew that Sam was stealing from him. He told Sam to get it into the account and he agreed. Beckett and Gates go through the details of what they have so far and Beckett says that there is a piece to the puzzle that they are missing. She reminds Gates that Castle is good at getting the missing puzzle. She tells Beckett that he also throws in a lot of unneeded things into it too. She tells Beckett that they need to find out who Sam was with last. Beckett sees that he was scheduled for a massage. In Atlantic City, the guys go to the massage parlor and realize that Sam couldn’t have transferred the money because it was not a normal massage and his hands were preoccupied. The masseuse says that Nadine made the appointment rather then Sam’s assistant. They realize that Nadine had something to do with Sam’s murder and go out to find her. They see a black SUV drive up and take Nadine. Castle realizes that they are not going to the Burlesque Show later. Meanwhile, Alexis’s friend comes over and says that she has “Bridesmaids”. She says that one of the girls is going to have her boyfriend pick up his jacket. Alexis suggest that they have the boys come over too.
Back in Atlantic City, the guys realize that Nadine is the thief who stole the $10 Million from the casino. They tell Turner and he kicks them out of the casino. They call Beckett and give her an update. Beckett tells them that Nadine called inside the casino right before getting taken. They realize that it is to Daniel Sullivan, Turner’s tech guy. Beckett says that she is going to drive down there since they are kicked out. Meanwhile at Castle’s place, the little gathering has already turned into a small party. Alexis talks to Bryan, a popular jock at her school. She goes up to her friend and she tells Alexis that they updated facebook saying that there is a party at her house. Alexis realizes that the small gathering has turned into a huge party. Back in Atlantic city, Castle says that he has an idea on how to get in unidentified. They dress up like Elvis impersonators and get past security. They go to Daniel and he admits that it was him and Nadine who took the money because Sam made advances to Nadine to go out with him or else he would evict Nadine’s parents, who have a place that they are renting in the property that Sam wanted full rights to. Daniel says that Sam told him that they stole the wrong person’s money. The security come in and takes them out. They stop Castle from leaving. Back at Castle’s house, the party is getting out of hand and Alexis tells everyone to get out. Castle gets taken to Turner’s office. He says that he wants the money back. Castle realizes that Turner and Sam borrowed form the Mafia and that is why they are touchy with the money. Castle says that he can get his money back.
Outside the casino, Beckett arrives as Ryan and Esposito are kicked out. However, Castle comes up and says that he knows who killed Sam. Tommy Moretti, a crime boss, is the one. Beckett tells Daniel that he is going to meet with Tommy and then they are going to arrest him for Sam’s murder. Daniel meets with Tommy and asks to see Nadine. He has his guards come out with her. Daniel wires back the money and Nadine is allowed to go. Beckett and Castle go up to Tommy and he says that he didn’t kill Sam. He says that his ex-wife signed the deed to the property. Beckett realizes that she was lied to. Beckett goes back to the station and talks to Rebecca and says that they found the deed in the trash bin. Rebecca says that she killed Sam based on the fact that Sam threatened her life and that she saw her opportunity. Gates goes up to Beckett afterward and tells her that she did a good job without Castle. She says that Castle is good because he is not a cop and says that she gave them a couple days off to give Ryan and “unofficial” bachelor party. Later, Castle comes in hungover and Alexis has everything cleaned up. Castle doesn’t suspect anything and the episode ends.