There was a much bigger war going on during the episode 14 of "Supernatural" Season 12. It's the war between the Winchesters. Sam and Dean learned about Mary's affiliation with the British Men of Letters, and although she claimed that she is only working with them to foster a better way of hunting, Dean certainly does not believe it.

According to Entertainment Weekly, the revelation that Mary has been working with the British Men of Letters was made last week, and episode 14 showed that Mary has made her choice, and she chose the Men of Letters over her sons, so as far as Dean is concerned, it would do better if Mary would just leave their lives. "There's the door," Dean said.

The BMOL obviously wants Dean and Sam on their side, because once that happens, then all the other American hunters will follow. But, they are underestimating Dean's stubbornness. When Season 12 started, fans had the impression that the BMOL is a group of villains, but right now, it is very unclear as to what their true agenda is.

Episode 14 titled "The Raid" presented the Men of Letters as an alternative to the Winchesters. In many ways, if not all, they are not better or worse than Dean and Sam - they are simply different. They have advanced technology and they are organized, while the hunters rely on being street smarts.

Now, the new promo for the upcoming episode has been released. According to ComicBook Movie, "Somewhere Between Heaven And Hell" will show a hellhound is on the loose, and it looks like Dean is blood-soaked and is just an inch away from death. The official synopsis of "Supernatural" Season 12 episode 15 says that an attack by an invisible hellhound leads Dean andThe t Sam to investigate the mystery.

Meanwhile, two of Crowley's own personal demons unearthed what he has been hiding, while Castiel gets a lead on Kelly Kline. "Supernatural" Season 12 episode 15 is set to air on March 9.