As Supernatural season 9 approaches, we’ve rounded up some of the most important teases going into the premiere.

Season 8 ended with Metatron expelling all the angels from Heaven. Meanwhile, Dean prevented Sam from completing the third trial to seal the gates of Hell permanently, but Sam was left deathly ill in the wake of the aborted trial.

When the ninth season begins, Sam will have survived the trial. However, TVLine reports that Dean will have something to do with his survival, and that will be a secret that may cause a rift between him and Sam.

According to executive producer Jeremy Carver, Dean will open the season “in a slightly different position, one where it’s his decision driving great importance and weight on their relationship.” Carver adds, “It’s a heavy weight to bear, and it has a great effect on their relationship.”

Meanwhile, the brothers will also be forced to deal with the fallout of the angels falling to Earth. There will be “a lot of players for the throne of who’s going to rise to the fore here,” Carver says.

The players will include Ezekiel, “a dignified warrior angel injured in the Fall” who will be played by Battlestar Galactica alum Tahmoh Penikett.

Beyond Ezekiel, season 9 will explore some “really interesting, really neat angels,” Carver previews. “Wherever we can dive into Biblical references, we do and then we turn that the way that we need. Some of the angels that we see…have deep roots in angel mythology.”

Felicia Day will also be returning in season 9. She will appear in episode 4, titled “Slumber Party,” which will tackle The Wizard of Oz. The episode will feature flashbacks to 1935 and reveal “the first Men of Letters ever to occupy the bunker,” teases Carver. “It’s a lot of fun and heartfelt.”

Supernatural season 9 premieres Tuesday, October 8 at 9:00 p.m. ET on The CW.

Edited by Karen Rought