Dean accidentally kills Castiel, and is tormented by grief and guilt afterwards. Dean becomes convinced Cas still exists somehow, and that he will be resurrected; Sam's not so sure, but is determined to help his grief-stricken brother recover. Meanwhile the Darkness is eating away at Creation, and soon both brothers realize they may have to embark on their longest and strangest journey yet. This time they might not come back. Will they have to fight their last battle without Castiel?
Dean accidentally kills Castiel, and is tormented by grief and guilt afterwards. Dean becomes convinced Cas still exists somehow, and that he will be resurrected; Sam's not so sure, but is determined to help his grief-stricken brother recover. Meanwhile the Darkness is eating away at Creation, and soon both brothers realize they may have to embark on their longest and strangest journey yet. This time they might not come back. Will they have to fight their last battle without Castiel?