Supernatural Spoilers: Dean and Sam get Dark at the Season Finale; Dean Kills Sam for Salvation

By Saff Writer

Apr 10 2015, 05:36 AM EDT

Supernatural returns with an all new episode on April 15 following a brief hiatus. The new episode is entitled Book of the Damned and Felicia Day returns as Charlie to help the brothers battle against the Mark of Cain.

Spoilers for Supernatural reveal that Charlie calls Sam and Dean to inform them that she was able to locate the Book of the Dead which is the key to remove the Mark of Cain. The brothers rush to her after knowing that she was shot by a Jacob Styne who claims that his family is the rightful owner of the book. The man swears never to stop until he reclaims the book for her.

As a brief recap, Dean continues to struggle with his condition during this arc but spoilers show that he does not get any better. It is said that the only way for Dean to be cured of the Mark is for him to kill his own brother. Cain sees the older Winchester as his protégé and just like Cain who killed his brother Abel, Dean is expected to succumb to the same murderous path.

One exciting Supernatural Season 10 spoiler is revealed by Jared Padalecki who plays Sam Winchester. He mentions that the younger Winchester goes "dark" in the last episode of Season 10.

"Sam does have a lot of darkness in him, so does Dean. I think it's one of the themes that, as long as Supernatural is alive, that theme is going to be around. Both of these guys are struggling with their demons, struggling with their past," Padalecki discloses in an interview.

Furthermore, Jared divulges in the same interview with Seattle's Salute, that the Supernatural team is currently filming the last few episodes of this season which he dubs as one of the most intense and demanding he have had thus far. At the same time, Jason Fischer, the show's production coordinator teases that the ending will be shocking and surprising. Many Supernatural avid fans rumor that the last episode of this season is more haunting and dramatic that Season 9 finale episodes where Dean transforms into the Knight of Hell.

The finale titled My Brother's Keeper airs on the 20th May on The CW at 9PM.