Howard dresses as Sheldon for Halloween at work, hurting Sheldon's feelings. When Howard does not apologize, Amy and Sheldon dress as Bernadette and Howard at Penny and Leonard's party, angering Bernadette. Sheldon and Bernadette later bond over their painful childhood memories. Leonard is upset that Penny does not seem to remember that their first kiss was on Halloween. Penny later admits she does remember, but does not like to think of their first kiss as an unromantic drunken hookup. She likes to imagine their first kiss was one they shared on Leonard's birthday, which pleases him.
While opening their wedding gifts, Sheldon and Amy cannot figure out the purpose of the glass shard Leonard and Penny gave them. They decide it must be a clue to a scavenger hunt to the real gift. They eventually end up in the coffee shop where they first met and find a locket in the lost and found that they think must be the real gift. The glass shard was actually a crystal chakra wand that Raj gave as a gift to Howard and Bernadette, who then re-gifted it to Leonard and Penny, who finally passed it on as a joke. Leonard and Penny find it less funny when they are given a coded thank-you note they have to use to unlock their WiFi. After making out with his employee Denise at Sheldon and Amy's wedding reception, Stuart finally asks Denise out on a date; while preparing for the date, he has a spray-tan accident, but she just finds it funny and still goes out with him. Raj is depressed everyone else has a relationship and asks his father to arrange a marriage.
Sheldon needs half a billion dollars to prove his latest concept of string theory, which the University cannot afford to fund. Crowdfunding and selling some of his most valuable comic books to Stuart give him a small start. When Raj mentions gambling in Las Vegas, Sheldon goes there but is caught calculating odds by security before he can make any bets. Meanwhile, Amy takes Penny and Bernadette shopping for her wedding dress. She loves an old-fashioned one that the other girls admit that they find ugly, though Penny assures Amy she can make her own decisions about her wedding. Sheldon, however, comes home and sees Amy in the dress and loves how she looks.