Sam (Jared Padalecki) and Dean's (Jensen Ackles) relationship will be tested in the upcoming season of "Supernatural."

The Winchester boys are set to be back in October with all-new episodes for the long-running CW series. There have been a lot of spoilers for the upcoming storyline and most of them suggest that the brothers will have one of their toughest seasons yet. For one, Sam was abducted by the Men of Letters, a covert British organization that specializes in anything supernatural. They sent a dangerous emissary last season - Lady Toni Bevell (Elizabeth Blackmore).

Bevell shot Sam in the chest and it has been teased that she would bring him back with her, where the society could teach him a valuable lesson. It will be Dean's job to hunt down his brother's kidnappers.

Showrunner Andrew Dabb said in a recent interview (as per Enstarz) that Dean would move heaven and earth to find Sam. When they do meet again, however, they would have a difference in opinion regarding what to do about the Men of Letters.

"Initially, Sam is in trouble and Dean is extremely driven to save his brother. As this thing becomes more personal, and we come to understand the British Men of Letters and their point of view, our guys will have different reactions. I believe when the cards are down, Sam and Dean are on the same page all the time, which is to do the right thing. But what is the right thing for either one of them is not always agreed upon," Dabb explained.

Spoilers suggest that Sam will surprise Dean by siding with the organization. It appears that he will begin to understand where the group is coming from. This will enrage Dean, as he can see Sam was tortured. Will Sam soon join the organization? Aside from their spat over the Men of Letters, the boys will also squabble over the return of their mother, Mary (Samantha Smith). There is the obvious question on what happens to her now that she has been resurrected. As seen in the promo, Dean and Sam's mom appears lost and unable to grasp the sudden changes in her life.

"Supernatural" returns on The CW on Oct. 13 at 9 p.m. EDT.