At the Beaumont Hotel, bride-to-be Kyra Blaine (guest star Alyssa Milano) knocks on her tardy bridesmaid's door. Sophie Rosnon isn't answering, but that's only because she's dead in a closet. Sophie was choked from behind and one of her earrings is missing. When Castle arrives at the crime scene, we realize he's a friend of the bride. Actually, they are way more friends. For Rick Castle, Kyra Blaine is the one that got away. Uh oh.
Lanie discovers a zigzag of gouges cut horizontally between the victim's shoulder blades. Interviews with wedding guests reveal that Sophie tried to back out of being a bridesmaid, but changed her mind last minute. At the bridal suite, Castle and Kyra catch up until her fiancé, Greg Murphy, shows up. Judging by the tension in the room, it pretty obvious why Castle's wedding invitation got lost in the mail.
A groomsman named Mike Weitz is missing. Greg's Uncle Teddy says the last time he saw Mike, he was with Sophie at the hotel bar. Mike's card key shows he last entered the room at 2 AM. A video from the rehearsal dinner shows Sophie leaving to meet a drug dealer in the hotel lobby. She was buying roofies. Beckett and Castle find Mike in a locked in a hotel storage closet. Sophie spiked his drink to knock him out. So, if Mike was passed out in a closet, who swiped into his room at 2 AM?
When Beckett and Castle search Mike's room, they notice the door to the adjacent room is unlocked. They head into the next room and quickly discover Sophie's missing earring on the floor. Any guesses as to who's staying in the adjoining room? If you said Kyra's fiancé, Greg, you'd probably make a pretty good homicide detective.
Greg admits that Sophie snuck into his room trying to seduce him while he was sleeping. Confused, he knocked her away (making her lose her earring). After he professed his love for Kyra, Sophie rushed out. Castle doesn't buy it. It's obvious to Greg that Castle still has feelings for his bride-to-be. It's obvious to Beckett, too. She tells Castle that he's too close to Kyra to be objective. He should stay away from her. Think that'll happen?
That night, Kyra calls Castle. She's worried her fiancé could be a murderer. Hey, every relationship comes with baggage, right? Castle suggests they meet on the same romantic rooftop they used to visit back when they were in college. There, overwhelmed by their emotions, they share a passionate kiss. Castle knows he shouldn't have done it, but at least they were on a secluded rooftop. Who would know? Detective Kate Beckett, that's who. She was having Kyra tailed and has surveillance photos of that "secluded" smooch.
Beckett claims she had Kyra followed because she's a murder suspect. Castle seems think there may be more to it than that. We kinda get that feeling, too. After all, at one point Beckett remarked that Kyra was different from Castle's ex-wives. When he asks what she means, Beckett thoughtfully says, "She's real. I didn't think you went for real." Well, Rick, you don't get any realer than Kate Beckett. We're just saying...
After talking with the guests, the team discovers that although Sophie was supposedly broke, she had been spotted spending lots of money. Ryan pulls a surveillance tape from the bridal shop, where the team watches as Greg's Uncle Teddy buys Sophie her bridesmaid's dress. Beckett believes that Uncle Teddy paid Sophie to try and break up the wedding. But why?
As it turns out, Uncle Teddy is executor of Greg's trust fund, which was to be transferred to Greg's control on his wedding day. Teddy embezzled money and hoped to buy time by bribing Sophie into ruining the wedding. But when Greg resisted and said he loved Kyra, Sophie changed her mind. Uncle Teddy's only option at that point was to murder the bridesmaid. The proof comes when they discover that his metal tie tack cut into Sophie's back when he choked her from behind. Looks like there will be one less guest at the reception!
Castle realizes that Greg is a good man. Kyra knows that and she loves him. But that won't stop her from thinking about her favorite mystery writer from time to time. Kyra stops by Beckett's desk to say that Castle is all hers. The befuddled look on Beckett's face is priceless. When Kyra and Greg finally tying the knot, the blushing bride tosses the bouquet which lands squarely in Beckett's hands, much to Castle's delight. Ours, too.