A Knight of the Seven Kingdoms

Will Byers goes missing, and his mother Joyce communicates with him through lights, while friends Mike, Lucas, and Dustin find Eleven, a girl with psychic powers.

Will is possessed by a shadowy entity called the Mind Flayer, and a new girl, Max, joins the group.

The Mind Flayer returns, possessing Billy (Max's brother) and creating a new physical form. A secret Russian base is discovered under the new Starcourt Mall.

The group is separated between Hawkins, California, and Russia. A new, human-like villain named Vecna kills teenagers in Hawkins to open a gate.

It follows the crew in a besieged Hawkins fighting to destroy Vecna and the Upside Down for good. The season focuses on a final battle, with the town under military quarantine while the party attempts to sever the connection between dimensions