(CNN) -- Fans of "The Big Bang Theory" gathered at Comic-Con for a panel about what happens inside the writers' room of the the mega-popular CBS series, and they got more than they bargained for when some special guests made surprise appearances.
Melissa Rauch, who plays Bernadette Rostenkowski, moderated the panel. Johnny Galecki, who plays Leonard Hofstadter, arrived in full "Star Wars" regalia, and the iconic physicist Stephen Hawking recorded a video message that featured him singing the show's theme song.
In the hour-long conversation, the actors, writers and producers teased details about the show's upcoming seventh season, which premieres on September 26.
They confirmed Leonard will take the offer from Stephen Hawking that was presented in the sixth season's finale. Kunal Nayyer's character Raj Koothrappali will be figuring out how to speak to women without the influence of alcohol, and Bernadette and Amy (Mayim Bialik) may take their first trip away without Penny (Kaley Cuoco).
The real question, one that has been plaguing fans especially since last season, is whether Jim Parsons' Sheldon Cooper and Amy will finally consummate their romantic relationship.
"I"ll use Sheldon's words and say 'It's a possibility,'" writer Steve Holland said.
"I think part of the charm of their relationship is this glacial pace," creator/producer Bill Prady said. "I think there's such a sweetness to that. I think one of the virtues is how long it lasts. And it also means the show can last a lot longer."
The writers also addressed whether the cast would ever find themselves at San Diego Comic-Con in an episode of "The Big Bang Theory."
"From the first time we came here we said 'Oh my God we have to figure out a way to film an episode at San Diego Comic-Con,'" Prady said. "But we don't go into production until August so at the beginning of summer the cast goes off. Everybody's in crazy places. And then the other problem is that we shoot on a stage, and we're just not very good at filming out in the real world. So it remains a really good idea we have yet to find a solution to."
Comic-Con is certainly the right place for this particular group of writers, however, who do a lot of research on the various science and geek topics that are integral to the show.
"We're all pretty comfortable with the geekery," Holland said. "Sometimes we have ideas from articles we've read or we have a vague notion of, or sometimes we put in brackets 'Science to come.'"