30 Rock actor Jack McBrayer (Kenneth the page) and co-executive producer Robert Carlock spoke with reporters via conference call about the show’s final season, upcoming guest stars and the atmosphere on set.

On the heels of Tina Fey fleshing out upcoming guest star Ryan Lochte’s role as a “sex idiot,” McBrayer offered more insight into guest stars Bryan Cranston (of Breaking Bad) and Catherine O’Hara’s (from all of those Christopher Guest movies you love) characters. O’Hara will play Kenneth’s mom and Cranston her “friend” (re: Kenneth’s step-dad) Ron.

“Kenneth just has so much baggage with Ron that he can do no right in his eyes,” McBrayer said. “[O’Hara and Cranston] were so funny and pleasant to be around. That was one of my favorite days shooting.”

Kenneth’s mom’s “friend” Ron has long been one of the funnier mentioned, yet unseen characters of the show’s run, trailing only with Astronaut Mike Dexter in ratio of laughs to 0 screen time. Introducing an actor to play him could have ruined all the fun but if 30 Rock is going to do so, they could have done worse than the guy with three Emmys.

Carlock reiterated Fey’s claim at the Emmys that the show’s end isn’t set in stone yet, saying that they are currently shooting episodes four and five.

“We don’t quite know what the ending is,” he said. “We have a shorter runway than usual and we want to give everyone closure in their own weird way. Though in the first season, Jack said everyone would die by Kenneth’s hand or they’d be working for him and we want to achieve one of those goals.”

Despite it being the last season, McBrayer maintained that the cast and crew hasn’t felt any differently about their work…especially considering the show was often on the bubble throughout its run. Still, the end does loom in its own way.

“It kind of feels like your senior year of high school,” McBrayer said. “You know that on graduation day, you’re going to be choking back tears and hugging people you’ve never even spoken to.”