"Supernatural" Season 12 Episode 15 will feature brothers Sam (Jared Padalecki) and Dean Winchester (Jensen Ackles) going on a hellhound hunt following an attack, while a new lead about Kelly Kline (Courtney Ford) will be uncovered. Meanwhile, a secret of Crowley (Mark A. Sheppard) will be revealed.

According to a report from ComicBookMovie, the synopsis for episode 15, which is entitled "Somewhere Between Heaven and Hell," will have the brothers investigate an invisible hellhound who attacked a campsite. And this hellhound is not a new one, but likely something the brothers have already encountered in the past.

The report said that the way Crowley described the hellhound shows that's it's likely the same one that attacked Dean and tore him to shreds in the finale of season 3. Aside from the two brothers investigating a hellhound attack, Crowley will also be dealing with his personal demons on "Supernatural" Season 12 Episode 15.

The character's two personal demons get to discover a secret, as they'll get to see who he has been keeping captive. Lastly, Castiel (Misha Collins) finally gets a lead on Kline, who is the mother of Lucifer's child.

CarterMatt reports that this story about Kline is the most planted story in season 12. The story is also interesting because it relates to Castiel's past and Lucifer's world.

The report adds that the notion about Castiel is that can he separate himself from his past and from the world of Lucifer. The character feels responsible, being a representative in this world, but that feeling of responsibility is also acting as a big burden and pressure for him.

This episode will surely be a treat for the fans as a little bit of everything will be featured in it. "Supernatural" Season 12 Episode 15 will return on March 9, 2017. Check out the trailer for "Somewhere Between Heaven and Hell" in the video below.