'The Office': James Spader's Scranton ties and more from EP Paul Lieberstein

When we asked about how long "The Office" has been at work on its eighth season -- a couple weeks, is it? -- Paul Lieberstein gave a rueful smile.

The NBC comedy has been filming for a little more than a week, but showrunner Lieberstein and his fellow writers have been at work for a good deal longer than that. It's been an eventful off-season for "The Office," which has a new star -- James Spader is joining the show in the wake of Steve Carell's departure -- and will be writing Jenna Fischer's real-life pregnancy into the series.

Lieberstein tells Zap2it that early though it is on the new season, things are "pretty great," and he's liking what he sees from Spader and the returning cast.

"He's amazing," Lieberstein says of Spader, a multiple Emmy winner for "Boston Legal." "He brings so much. He brings his own acting process to it. The mix of our very kind of loose process and his very exacting process has created something -- it's a fantastic energy on set."

We'll learn in the season premiere that Spader's character, seen in last season's finale interviewing for Michael's (Carell) job, got that post but then quickly ascended the ladder to become CEO of Sabre, Dunder Mifflin's parent company. We wondered how the show would contrive to keep Spader around Scranton from week to week, but Lieberstein says there's no set pattern as to how much he'll be around.

"Sometimes he's in a couple of scenes, and some episodes he's not in -- but some he's in a lot," Lieberstein says. "I think family is a big draw for him. We're saying he's from the [Scranton] area, so he spends a lot of time supervising this branch."

The process that led to Spader being cast on "The Office" was "pretty open," Lieberstein tells us. After Carell decided to leave, there was agreement from the show's producers and NBC that "something had to happen," but there was no directive from above to go one way or another: "How it was going to come about, everyone was pretty willing to discuss."

Among the many guest stars in last season's finale, Spader seemed to create the most buzz among fans, and based on what little we saw of him, there's no question that he'll be playing a decidedly different character from Michael Scott.

"There was no question that James clicked on set," Lieberstein says. "He fit in our world and brought out a side to our characters that we hadn't seen before. He did something really unique, so we wanted to explore that."

As for Fischer's pregnancy, Lieberstein says it was a pretty easy decision to write it into the show, since it seems natural that her character, Pam, and husband Jim (John Krasinski) would be thinking about another child. Lieberstein also teased an upcoming Pam-centric storyline:

"We're going to do an episode where she doesn't trust how she's feeling toward anything, because her hormones are just running wild," he says. "There comes a point where she feels like everyone's obviously lying to her about something -- but Dwight [Rainn Wilson] doesn't, so she starts to think Dwight's the only person she can trust."

"The Office" premieres Thursday, Sept. 22 on NBC.