'Supernatural' season 12 spoilers: Sam and Castiel to fight?

Castiel (Misha Collins) will have a little disagreement with Sam (Jared Padalecki) in the upcoming episode of "Supernatural" season 12.

According to the synopsis of the episode titled "The Future," the younger Winchester brother, Sam, will come up with a plan to stop the birth of Lucifer's (Mark Pellegrino) baby since both he and his brother Dean (Jensen Ackles) know that the nephilim should not be given the chance to live.

Castiel, meanwhile, has a different plan brewing for Lucifer's baby mama Kelly (guest star Courtney Ford). But his plan will clash with the Winchesters. This will cause a little problem with Sam.

On the other hand, the promo trailer of the upcoming episode reveals that Castiel will visit the place of the demon named Dagon (Ali Ahn) alone to search for Kelly. Dagon initially pretended that she will take care of Kelly, but the trailer reveals that she will warn the upcoming nephilim's mother that she will die while giving birth to her child since all human mothers of nephilims are supposed to die due to pain.

The trailer also shows that Dagon will try to hurt Castiel, but Sam and Dean will suddenly arrive to rescue their friend. They will try to shoot her with their guns and colt, but it will not have any effect on her. In another scene, Castiel will tell the Winchesters that the female demon is very powerful and they will have a hard time defeating her since the real colt that could end Dagon's life is stolen. But they have to kill her first before they can finally get to Kelly.

Meanwhile, the synopsis also reveals that Kelly herself will make a daring move regarding the future of her upcoming baby.

The CW will air the next episode of "Supernatural" on Thursday, April 27, at 8 p.m. EDT.