Season synopsis
Contains spoilers for this season and earlier seasons.
Dean finds Mary alive after Amara’s parting gift, while Sam is held and tortured by Lady Toni Bevell of the British Men of Letters. The organization has watched the Winchesters for years and wants to impose its controlled approach to hunting in the United States. Mary has to reckon with a world decades beyond the one she left, and she returns to hunting before becoming entangled with the British group. Sam and Dean’s effort to find her and resist the organization brings American hunters into the conflict.
The British Men of Letters turn on the hunters, and Sam takes responsibility for organizing a counterattack. Dean escapes the bunker with Sam, then joins him in trying to protect their allies and reach Mary, who has been brainwashed into hunting them. With Toni’s help, Dean enters Mary’s memories and helps her break through the conditioning; Sam leads the hunters against the British compound. Their victory does not end the family’s danger: Lucifer is loose again, and his child with Kelly Kline is close to being born.
Kelly chooses to carry the pregnancy to term, and Castiel promises to protect and raise the child. The baby’s power opens a rift to an alternate Earth where the Winchesters were never born and angels have devastated the world. Lucifer follows the brothers there; Crowley sacrifices himself to close the rift, but Lucifer returns and kills Castiel before Mary knocks him back through the closing portal, and Lucifer drags her through with him. Kelly dies in childbirth, and Sam finds her son Jack already grown.