WARNING: This article has spoilers for Supernatural season 15 episode 15. Read at your own risk.

Supernatural season 15 episode 15 is airing this week on The CW. The episode, titled "Gimme Shelter," could reveal some big moments from the past. Castiel (Misha Collins), in particular, is seemingly ready to reveal the deal he made with The Empty.

Based on the promo of Supernatural season 15 episode 15, something bad may happen to Castiel along the way. His current situation is a bit concerning and it remains to be seen whether or not he'll make it out until the end. There could be unexpected twists and turns since we're nearing the series finale.

The idea of losing a character is worrying to a lot of fans out there. Most lives are in jeopardy, especially since the biggest adversary is Chuck/God (Rob benedict). The good thing is that Castiel won't be leaving Sam (Jared Padalecki) and Dean (Jensen Ackles) even if he's in danger.

Castiel was still mentioned in the synopses of the next two episodes. That means that everything's going to be fine within this episode. He's been on the show for a long time and became one of the essential characters. It's hard to imagine the series ending without him in the picture.

In addition, Castiel is on a mission with Jack (Alexander Calvert) in this week's episode. According to the synopsis, the two will be working together in order to solve a particular case which involves the members of a local church.

Meanwhile, Supernatural season 15 episode 15 marks the return of Emily Swallow as Amara. She has an inherent connection to God, something that will be further explored. The synopsis notes that Sam and Dean go on a journey to search for her.

Aside from her relationship with God, Amara's got a history with the Winchester brothers, as well. However, their hunt for her won't be that easy as they may encounter several setbacks along the way. Some mythical creatures could halt their journey moving forward.

Amara is set to appear for another episode after this one. That means we could see more stories coming for her along the way. She could also bring more chaos to Sam and Dean, especially since she's known as The Darkness. But, for now, it's yet to be seen how the Winchesters could find her.

Supernatural season 15 episode 15 is set to air on Thursday, Oct. 15, on The CW.