The third episode of the long-running television show "Supernatural" has left protagonists, Dean Winchester, played by Jensen Ackles, and Sam Winchester, played by Jared Padalecki, in a state of grief after the numerous deaths that occurred in the previous episodes. The events leading to the demise of these people has triggered Dean and Sam's own inner demons and struggles, which may still persist in the upcoming episode.

In a report by Cartermatt, the synopsis for episode 4 titled "The Big Empty" states that the Winchester brothers along with Jack, played by Alexander Calvert, conduct their investigation as to what caused the death of the patients of Mia Vallens, played by Rukiya Bernard. In the process, they are faced with their own unresolved emotional issues – most of which stemmed from past events.

Things are not exactly easy now either, since Jack is trying his best to change his eventual evil-natured future, being Lucifer's son and all. However, the show does a good way of delivering the heavy and emotional aspect of the story in this light rather than just creating an episode just for flashbacks. How will the Winchesters and Jack come out of the integral moment of introspection? Will they become closer than ever?

One other unmistakable thing that longtime fans of the show are awaiting is the return of the archangel, Castiel, played by Misha Collins. It was already highly speculated that Castiel would be coming back to the show.

According to Den of Geek, the show runners did a good job of making fans and audiences think that Castiel would never be returning to the show again. However, it already seems like Castiel will be making a return after Jack whispered his name. It was seen that Castiel is in a dark void of nothingness when he regains his consciousness. Could the void be "The Big Empty?"

"Supernatural" airs on Thursdays at 8 p.m. EDT on The CW.