VIDEO: Sneak Peek - James Earl Jones Guest Stars on THE BIG BANG THEORY

On the next episode of CBS's THE BIG BANG THEORY titled 'The Convention Conundrum,' after the guys can't get Comic-Con tickets, Sheldon tries to hold his own convention and winds up spending a wild night with James Earl Jones. Meanwhile, the girls see if they can act like "grown-ups."

The episode airs Thursday, Jan. 30 (8:00 – 8:31 PM, ET/PT) on the CBS Television Network. James Earl Jones and Carrie Fisher appear as themselves. Get a sneak peek below!

Leonard and Sheldon are brilliant physicists – geniuses in the laboratory, but socially challenged everywhere else. Enter beautiful, street-smart neighbor, Penny, who aims to teach them a thing or two about life. Despite their on-again, off-again relationship in the past, Leonard believes he's found true love with Penny. 

Even Sheldon has found a female companion, entering into a "Relationship Agreement" with neurobiologist Amy Farrah Fowler. In their free time, Leonard and Sheldon continue to enjoy frequent trips to the comic book store and fantasy role-playing games with their ever-expanding universe of friends, including fellow scientists Koothrappali, Wolowitz and Wolowitz's adorable microbiologist wife, Bernadette.