What can we expect on the Supernatural season finale? Who is about to be featured in his own episode? Where will the brothers travel to next?

All of these questions and more were at the center of the show's panel discussion yesterday afternoon at Paley Fest, an event hosted by Maureen Ryan of AOL TV and one that featured a clip from the April 22, western-themed installment.

Watch the boys head back to 1861 and then check out a few scoop-worthy excerpts from the discussion below.

Hyped as "the emotional key-up" for the May 20 finale, "The Man Who Would Be King,” will focus on Castiel, going into the “fruition of some serious friendships and where they go," teases producer Ben Edlund.

We'll also meet Castiel's trusted lieutenant Rachel, played by Sonya Salomaa.

Jensen Ackles and Jared Padalecki didn't reveal many spoilers, but series creator Eric Kripke chimed in: “There’s a few curveballs coming."

Kripke also wrote the two-hour season finale, said everything will come "to a head" -  the war in heaven, the showdown with the Mother of All, and the story behind Purgatory - and added the final episodes aren't really related to each other.

“There’s so many mythology balls up in the air. It feels like two episodes that each have their own story. It’ll be awesome in reruns!”

Added producer Sera Gamble: "There will definitely be deaths. I would say that the last couple of episodes are pretty dark. The situation is rather desperate for Sam and Dean and they truly have to ban together to get the job done."

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.