The Dixie Trek Convention was an event held in 1995 for Star Trek.
Before the show
In 1995, Sheldon traveled for 10 hours on an a bus, during which he had to twice violate his personal rule of relieving himself on board a moving vehicle and then he finally arrived at at the 4th Annual Dixie Trek convention where he expected Wil Wheaton to show up and sign Sheldon's action figure, but Wheaton didn't show up and this made Sheldon feel betrayed and thus, Wheaton landed on Sheldon's mortal enemies list.
In "The Creepy Candy Coating Corollary" Sheldon and Raj enter the Mystic Warlords of Ka'a tournament at the comic book store and play against Wheaton and Stuart, the store's owner and Sheldon and Raj's friend. Sheldon only joined because he wanted to confront Wheaton over the incident. In the final match, Sheldon is about to defeat his hated rival after finding out what cards Wil has to which Wil replies "I think he's got me" and Sheldon recapping the entire incident, but Wheaton tricks him once more by telling Sheldon his grandmother had died shortly before the convention and that he had to go to her funeral and Sheldon prevails, since he also has affection for his grandmother. It is revealed that this ruse was a scam to win and upon losing, Sheldon tenses up and screams angrily, "WHEATON!" just as James T. Kirk yelled "Khan!!"
In "The Russian Rocket Reaction", Wheaton invites Leonard and Sheldon to a party at his house. Leonard intends to go with Raj and Howard (until he tells everyone that he got offered to go into space), leaving Sheldon feeling betrayed. However, Sheldon has a change of heart when he finds out that Brent "Data" Spiner will be attending. It is revealed that Wil attended Hollywood Squares instead. At the party, Wheaton gives Sheldon the gift that he had always been waiting for, a signed, mint-condition Wesley Crusher action figure, saying, "To Sheldon, sorry it took so long. Your friend, Wil Wheaton." Sheldon immediately forgives him and gives him a hug. However, Brent Spiner comes along and sees the action figure. He opens it. This now lands Spiner on Sheldon's mortal enemies list.