Paget Brewster, Joel McHale Paget Brewster, Joel McHale

When Season 6 of Community debuts on Yahoo! Screen next year, the comedy will be without Yvette Nicole Brown (Shirley) and Jonathan Banks (Professor Hickey). (She left to take care of her ailing father; he is committed to AMC's Better Call Saul.) As he worked to fill the cast openings, executive producer Dan Harmon was inspired by how another sitcom handled its own transitions. "I looked at Cheers losing Coach and going to Woody as the example of thinking laterally," he says. "The real job is how to fill the [character] vacuum, rather than replace the person."

To embody the moral center held by Shirley, Harmon and executive producer Chris McKenna brought on Criminal Minds' Paget Brewster as Francesca "Frankie" Dart, a consultant hired to help shape things up at the underachieving Greendale Community College. She immediately butts heads with other characters and runs up against the school's dysfunctional Dean Pelton (Jim Rash).

Exclusive: Community Hires Two New Series Regulars

"We wanted to have a female character that represented the threat of disappointment," Harmon says. "Someone who, if you make the wrong move, you could let them down."

Keith David (Enlisted) steps in as Elroy Patashnik, a washed-up inventor who enrolls at Greendale to reinvent himself. "We needed someone of this age range because the human experience comes in stages," Harmon says of including a character in the over-50 demographic. That position was previously filled by Banks, and before him by Chevy Chase's Pierce.

Both actors are familiar to Community fans: Brewster guest starred as an IT staffer last season and David narrated a faux Ken Burns-style documentary in the Season 3 episode "Pillows and Blankets." Harmon isn't too concerned about using the same actors in different roles: "[Deadwood's] David Milch does it, so we can do it," he quips.

Exclusive: Jim Rash and Nat Faxon to Direct Community Episode

David says he was already a Community fan because he's pals with Brown, who turned him on to the show. "I like the show because I think it's smart. It's not just slapstick and silly, it's based in something," says David, who connects with Elroy: "I'm the guy who did all these wonderful ideas that didn't pan out. I'm interested to see how we explore that. I understand something about being a dinosaur in a way."

Brewster previously worked with Harmon on his popular Los Angeles stage show Channel 101. "I'm still watching and re-watching every episode," she says of Community. "There's so much nuance, so much stuff going on that you do not realize or catch the first time."

The actress says she's game for anything. "Whatever they want I'll do," she says — with one caveat. "I hope I don't have to run around campus naked at some point. I shouldn't even say that. Maybe that's how it happens."

Subscribe to TV Guide Magazine now!