The Odd Couple kicks off its third season Monday night with more mismatched roommate antics from Oscar Madison (Matthew Perry) and Felix Unger (Thomas Lennon). Fans can expect the show's classic, traditional sitcom stylings to continue as Season 3 follows the ups and downs in Oscar's relationship with his girlfriend Charlotte (Teri Hatcher) and Felix's with his girlfriend Emily (Lindsay Sloane).

"Spoiler alert: it's going to be rocky," jokes Odd Couple executive producer Bob Daily.

As of now, The Odd Couple's third season will consist of 13 episodes, with the potential for more if CBS picks up the option. Which it might, if The Odd Couple continues to perform like it did in Season 2, which got better-than-expected ratings.

The show was rewarded with a slot on the network's fall schedule -- the first two seasons premiered in the spring -- so it's getting to do some seasonal things it didn't get to do before, including Halloween and Christmas episodes, Daily tells TVGuide.com. Daily is particularly excited for the Halloween episode, which will be a good parallel character-development episode for the two of them -- Oscar will try to prove that he can be a responsible grown-up by taking Charlotte's son trick-or-treating, while Felix will try to lighten up and prove to Emily that he has any sense of childlike fun.

Matthew Perry, Thomas Lennon and Teri Hatcher, <em>The Odd Couple</em>Matthew Perry, Thomas Lennon and Teri Hatcher, The Odd Couple

The other big change was the loss of Garry Marshall during the season's production cycle. The TV icon, who died in July at age 81, developed the original Odd Couple series starring Tony Randall and Jack Klugman back in 1970 and created many other series, including Happy Days. Marshall was an executive consultant for the new Odd Couple's first two seasons, pitching story ideas and jokes and entertaining the studio audience at tapings. He even played Oscar's father in one Season 2 episode.

"He made us so much better," says Daily. "It really was a blow. He was sort of our mascot/guiding light/the guy that always made us laugh."

There will be an episode that pays tribute to Marshall at some point in Season 3, Daily says.

Season 3 picks up three months after the action of the finale. Oscar and Charlotte are happy after getting back together, but Felix is in an emotional tailspin because Emily has been away in London on an internship. He's so distraught that his fastidiousness is slipping -- he's grown a beard. Things get even worse when Emily tells him she might be extending her stay to go on a business trip to Paris with her boss, a man named Fergus who Felix suspects is trying to steal Emily away from him. Felix and Emily's relationship could be in trouble, and Oscar is forced to choose between being a good, romantic boyfriend on his and Charlotte's three-month anniversary or helping his freaking-out friend.

Guest stars this season will include R&B group Boyz II Men -- who appeared at the behest of Odd Couple cast member Yvette Nicole Brown, who pulled some strings to make it happen -- and NBA star Chris Bosh, who will be a guest on Oscar's radio show, among others.

The Odd Couple premieres Monday, Oct. 17 at 9:30/8:30c on CBS.

(Full disclosure: TVGuide.com is owned by CBS.)