As one Winchester battles his demons, another still fears his own demon past on Supernatural.

Who Is 'Supernatural' Season 10's Big Bad? Jensen Ackles Teases Upcoming Reveal

Dean (Jensen Ackles) is currently waging war on the Mark of Cain, but he isn't the first of John's sons to have a little problem with his dark side. Sam (Jared Padalecki) has had demon blood running through his veins since he was six months old. Just because Moose's demonic side has lain dormant since his time in the Cage, that doesn't mean it can't rise again."

"I think it's still there," Padalecki recently told fans at Creation Entertainment's Salute to Supernatural in Houston. "I think, not to ruin the mystery of it, but because the season 5 finale was kind of the whole entire vision of [series creator Eric] Kripke's story, we had to do something, right? Had we kept it so in the forefront in season 6 it would have been hard to get around 'What about the demon stuff? What happened?' So they kind of changed Sam. But I think there, down somewhere, dormant. So maybe we'll see it."

'Supernatural' Star Jensen Ackles Talks Break From Mark Of Cain, Sam's Reaction To Working New Cases

For the meantime, however, fans should expect Sammy to play the levelheaded guiding light of the Winchesters. It seems only one brother can fall into darkness at a time, or else there would be no one ready to risk hell and high water to make sure the other one eventually reconnected with their humanity.

Find out more when Supernatural airs Tuesdays at 9 p.m. ET on The CW. Click the video below to see a preview for the series' next episode, "Halt & Catch Fire."

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