'Big Bang Theory' signals Season 10 won't be its last

BURBANK, Calif. — Over the past nine seasons,The Big Bang Theory pals have found relationships, marriage and even impending parenthood, fueling fan interest in the show, still TV's top comedy (Mondays, 8 ET/PT). Although major stars' contracts expire next May, actors and producers say they want to continue. Now it's a matter of negotiating the cost.

Season 10 storylines, including last week's ceremonial wedding vows for Penny (Kaley Cuoco) and Leonard (Johnny Galecki); Bernadette (Melissa Rauch) and Howard (Simon Helberg)'s impending parenthood; and plans for Sheldon (Jim Parsons) and girlfriend Amy (Mayim Bialik) to try living together, illustrate the series' evolution from its start, which featured awkward, single geniuses Sheldon and Leonard living across the hall from actress-waitress Penny.

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“The growth of all the characters makes them feel like real people that we know. They’re going through journeys in their lives, like any of us are,” says executive producer Steven Molaro. “People get married, people have babies, people die. The evolution of the stories and characters is key to the show’s longevity.”

But the evolution can be slow and fitful, a healthy recipe for comedy, Parsons says. “They’re living their lives and growing a little bit. The way people do, just a little.”

CBS Entertainment president Glenn Geller said in August that he'd like Bang to extend beyond Season 10, echoing comments from Warner Bros. Television, which has profited handsomely from the series, co-created by Chuck Lorre. "Everybody involved would like to see it keep going," Molaro says. But renewal comes down to  lots of money. Under the current three-year pact, Parsons alone earns $1 million an episode, which makes him the highest-paid actor on TV, Forbes says. (CBS and Warner Bros.are expected to share the cost of extending actors' contracts.)

“Talk of ending does seem premature to me, even a decade in,” Parsons says. “If (the writers) remain inspired the way they have, then there’s not a lot to do but just have fun, because the scripts are a pleasure to put on.”

Adds Galecki: “When you love the characters, you can do it for 10 years, for 12 years, for however long until you happen to fall out of love.”

As Bang picks up after the season-premiere wedding vows, the men will resume  working on their guidance-system invention as Howard deals with an imposing Air Force colonel (Breaking Bad’s Dean Norris).

And Bernadette will adjust to her pregnancy. “It’s been pretty well-known that she is not that big a fan of kids, and hadn’t planned on having one," Molaro says. "We’ll see how having this baby unexpectedly has an effect on her emotionally and professionally.”

Life for the characters will start to get very complicated when Sheldon and Amy, who lost their virginity last season, try moving in together. Sheldon has been sharing an apartment with married Leonard and Penny, so any change “touches everybody,” Molaro says.

“We will start to poke at living arrangements and how that might look and work down the line in what we will call an experiment,” Molaro says. “A pretty reliable trick with (Sheldon) is to couch things in science. Leonard actually gets him to do it by bringing it back to Star Trek.”

Bang works because it celebrates intelligence while also laughing at its pitfalls, says Kunal Nayyar, who plays Raj, a shy man who once could only speak to women while drunk but now has two girlfriends.

“We celebrate nerd culture and smart people,” he says. But “no matter how smart you are, you still have the same, if not more, problems.”