Twenty-three years ago, Sam Winchester (Jared Padalecki) and Dean Winchester (Jensen Ackles) lost their mother to a mysterious and demonic supernatural force. Subsequently, their father John (Jeffrey Dean Morgan, "Grey's Anatomy") raised them to be soldiers. He taught them about the paranormal evil that lives in the dark corners and on the back roads of America...and he taught them how to kill it.

Sam and Dean spent their lives on the road, cruising America's highways in their 1967 Chevy Impala, battling supernatural threats and searching for the demon that killed their mother. Together with their father, they closed in on that demon. A bloody battle ensued, and the demon killed John before escaping.

Grieving the death of their father, the brothers' mission to kill the demon - and every other evil creature along the way - continued. Meanwhile, they began to learn troubling details about Sam. They discovered that the demon they were hunting had a special plan with Sam at its center: to free hundreds of demons from hell, creating an unstoppable demonic army, and to make Sam the leader of that army. Horrified by its plan, the Winchester brothers fought the demon. In a climactic battle, they finally brought the demon down, but at a terrible cost. They were unable to stop the demon from unleashing three hundred powerful demons from hell. And in a shocking turn of events, Sam was killed in the fight.

Unable to go on without his brother, Dean made the ultimate sacrifice. He summoned a deal-making Crossroads Demon and exchanged his soul for the life of his brother. The deal brought Sam back to life-but left Dean with a single year to live.

Now, Sam and Dean face all-out demonic war. And as they work to stem the rising tide of demonic activity, they continue to travel the country, battling the supernatural wherever they go: changelings, cursed objects, vampires, witches, malevolent spirits, even a very unmerry Anti-Claus. Dean's clock is ticking, with Hell awaiting him in less than a year's time. Meanwhile, Sam still faces the fallout of the slain demon's plan to make him leader of the gathering demonic army. Wrestling many new questions about his destiny, Sam must uncover the dark secrets buried within his own past and within his family's history. And he must find a way to save his brother.