During the hour-long premiere of Season 8 of the "Big Bang Theory," fans of the popular series will finally find out what happened to Sheldon, who made a sudden departure on a train in last season's finale.

In the Season 7 finale, Penny and Leonard found Sheldon at a train station, right before he tried to escape Pasadena. According to the International Business Times, Sheldon "was overwhelmed with all the changes that were taking place around him, including the newly engaged Penny and Leonard's talk about moving-in together, without him, and the burning down of Stuart's comic-store."

In the first episode of Season 8, which is titled "The Locomotion Interruption," "Leonard and Amy take an unexpected road trip to Arizona to pick up Sheldon," revealed CBS in a press release. "Meanwhile, Penny interviews for a job at Bernadette's company, and Howard is weirded out by Stuart's relationship with Mrs. Wolowitz."

CBS also released the synopsis for episode 2 of Season 8, which will air following Episode 1. In the episode, titled "The Junior Professor Solution," once Sheldon returns to Pasadenam he will be forced to teach a class that Howard will enroll in.

"When Sheldon is forced to teach a class, Howard surprises everyone by taking it. Meanwhile, the tension between Penny and Bernadette gives Amy a chance to play both sides," states CBS.

According to other media sources, Sheldon and Amy's relationship will hit some rocky roads. Meanwhile, Raj's quest for love and romance will also be a featured story line in the upcoming seaon, reports DNAIndia.com

In an interview with Entertainment Weekly, executive producer Steve Molaro teased that a comic book store will make a comeback next season. "There will be a comic book store in the future, we're figuring out how exactly that will work out but the show will not go on without a comic book store, I promise you," the EP said.

"The Big Bang Theory" Season 8 premieres on Monday, Sept. 22, at 8 p.m. ET on CBS.