Detective Kevin Ryan is getting married to the love of his life-Jenny. Castle's plus-one for the wedding just happens to be the love of his life-Alexis. Beckett will be flying solo on the big day. Esposito is going dateless, too. He's looking forward to hooking up with one of Jenny's old sorority sisters until he learns Lanie is bringing a date. But there's no time for him to pout because, you guessed it, there's a murder that needs solving.
Michael Bailey was real ladies man until he took a naked plunge out of high-rise hotel room. Fingerprints on a wine glass lead the team to Holly Franklin, a founding partner in a prestigious law firm. The flustered attorney admits to sleeping with the victim, but she knows him by the name Jake Hendricks from Chicago. She claims the deceased got dizzy and accidentally fell to his death.
Lanie says Bailey was poisoned about 45 minutes before he met Holly by a substance that may have been hidden inside a protein shake. She also says the victim had sex with another woman in the hours before he died. Timelines suggest Bailey may have been poisoned by this other woman. Of course, the deceased lothario slept with many women, so there may be more than one out there who wanted this guy dead.
Bailey told his ladies that he was headed for Europe for a spell, but he never left New York. He had a fake ID bearing the Jake Hendricks name and 60 grand in cash. Bailey's boss, Seth Harris, says his employee took a leave of absence from his job as a junior analyst in his company's acquisitions department. Another company's COO, who was there making a difficult corporate deal, saw a woman trying to break in to his office.
The woman seen at Bailey's office is Colette Roth, an international flight attendant, who tells a wild tale about the victim being kidnapped by masked ruffians. Video footage proves that she is telling the truth. Castle has a theory that their victim may be a real-life Jason Bourne who was poisoned by another secret agent. Beckett is bummed that she can't think of a better theory.
The abduction Colette witnessed was actually staged by Bailey's buddies, who are part of a team of pickup artists. The fake kidnapping was simply to scare off Colette. Afterwards, Bailey's two pals serve as his wingmen as he used every move in the book to pick up a married woman who would never make it into Bailey's ledger of conquests. It's a compilation of ladies to which the author gave nicknames. Castle recognizes the woman listed as "Gyrating Jenny." She happens to be the bride-to-be of his good friend Ryan. Uh oh.
The woman Bailey picked up while out with his pals is publishing heiress Lisa Hill, who kicked him out of her place after she caught him on her computer. Bailey sent an email to himself containing classified documents that belonged to her hubby, who happens to be an investment banker tied to a big deal going down with Seth Harris. Bailey was using his pickup skills to do some corporate espionage. He was killed by the scorned COO of the business group trying to close the deal with his company. Case closed.
Remember how Jenny was featured in the victim's sex ledger? Well, Castle and Esposito wanted to tell Ryan. Beckett thought it would be best to keep it a secret. As it turns out, the debate about what to do was unnecessary. Ryan knew all about Jenny and Bailey. It was before they were exclusive, so all is cool. Everyone better get ready for a wedding!
Esposito shows up at the church with a tall beauty as his date. She's also his cousin. Lanie's companion is handsome doctor who happens to be a great dancer. That's why his boyfriend let her borrow him for the wedding. The two exes end up escorting each other into the church. As for Castle, his date canceled when she was invited to a Lady Gaga concert by a cute boy. Thankfully, Beckett's there to walk with him arm-and-arm down the aisle.