Castiel is an angel of the lord. When it is prophesied that he will fall in love with a human and that act will destroy Heaven, the angels close themselves off from Earth. Years later, demons are becoming more and more powerful, and without their adversaries, Heaven has decided to reopen. To ensure their safety however, they decide to kill the one angel that could ruin it all. Fearing for his younger brother's life, Gabriel takes Castiel and flees to Earth and the one brother who will help him: Lucifer.
Meanwhile, Dean and Sam Winchester's father hasn't been home in a long while. Fearing the worst, they contact their uncle, John's younger brother, Michael Henry Winchester. Michael discovers John has been possessed by the demon who killed his wife and is after Sam, so he moves the three of them to a small lumbering town to hide the boys. Unfortunately, it's the same town Lucifer has been hiding for the past couple years.
When their lives intersect, will it lead to more tragedy, or will the angels and Winchesters be able to save the world, and themselves?
It's been eight months since Dean Winchester was killed by rogue Angels. Order has been restored in Heaven and on Earth, but Dean's family is still dealing with their loss. But when Cas and Sam investigate an unusual case, they make an unsettling discovery: Somebody is looking for Dean Winchester, and they don't care what- or who- they go through to find him. Is Dean Alive? And if he is... can his family remind him of who he is?