In the final episode, Johnny Galecki's experimental physicist Leonard is getting a big job offer overseas, but he's not sure he wants to leave when his relationship with Penny (Kelly Cuoco) is better than ever.
“Leonard and Penny are in the best place they have been since they started dating,” executive producer Steven Molaro told TVLine. "He's a little nervous, because he doesn't want anything to get screwed up."
Simon Helberg, who plays engineer Howard, said Leonard's decision to take the job -- an expedition to the North Sea with Stephen Hawking -- will break new ground for the popular comedy.
"It is obviously going to have a ripple effect throughout all the relationships on the show," Helberg told Rolling Stone. "Then people get jealous, people get afraid, or nervous."
"There's a going-away party, and without saying anything that's giving away too much, there's definitely some groundbreaking events that nobody has ever seen on 'The Big Bang Theory' that will occur in this finale. It's an exciting one."
Check out a sneak peak, below.
But if "The Big Bang Theory" is leaving its characters in limbo over the summer, fans will have some fun new merchandise to geek out about.
CBS has inked a deal with Warner Bros. to produce a line of merchandise featuring the "Big Bang" guys mashed up with "Star Trek" and DC Comics superheroes.
The T-shirts and bobbleheads, to be sold at Hot Topic starting May 31, will feature Leonard, Howard, Sheldon and Raj dressed as Starfleet officers and as their favorite comic book heroes.