The Big Bang Theory Comic-Con panel today wasn’t billed as a chance to see some of the show’s stars, but two of them did show up and even Stephen Hawking made a surprise appearance.

A day after the show was nominated for the Outstanding Comedy Series Emmy, show co-creator Bill Prady and showrunner Steve Molaro teased fans on the show’s direction in what was supposed to just be a “writer’s room” talk, notes E! News. However, stars Melissa Rauch and Johnny Galecki made appearances, with Rauch moderating the panel. Galecki showed up in one of Princess Leia’s Return of the Jedi costumes and joked, “I just couldn't stay away.”

The biggest surprise had to come from scientist Stephen Hawking, who has appeared on the show. He appeared in a video, using his computer to ‘sing’ the show’s theme song.

According to The Hollywood Reporter, seven writers were on the panel, plus David Saltzberg, the show’s science adviser.

Molaro said that season seven will kick off with Leonard going on his sea research trip, working with Hawking. They will also look at Raj’s new ability - talking to women. And Bernadette and Amy will go on a trip together. But everyone wanted to know about where Jim Parson’s Sheldon was going with Amy in their relationship.

“It always baffles me how much Amy has gotten Sheldon to move,” Prady commented. “With Sheldon, you have a character who comes from a place of 'No, I'm not going to change.' It's a lot of interesting work in the room of, 'What if Amy did this.'”

They showed off the following highlight reel during the panel:

image: CBS