The heroes need to close the Gate to the Upside Down that the Russians secretly reopened under Starcourt Mall, because if it stays open the Mind Flayer, a giant shadow creature that controls people, will keep getting stronger. Joyce, Hopper, and Murray sneak into the Russian base, fight past guards, and reach the machine powering the Gate. Joyce must turn two keys at the same time while Hopper protects her from a Russian soldier, because if the machine isn’t destroyed the monster above will win. Eleven, Mike, Dustin, Lucas, Max, Will, Nancy, Jonathan, Steve, Robin, and Valerie face the Mind Flayer’s physical form when it crashes in to attack Eleven. She’s injured and weaker, so the others distract it with fireworks and cars. Billy, controlled all season, briefly breaks free when Eleven reminds him of his childhood and stands up to the creature to protect her. Valerie and later wake up separated—Valerie with a cut across her nose and after Billy knocked her out and took Eleven to sacrifice her to the Mind Flayer. Joyce finally turns the keys, destroying the Russian machine, the Gate closes, the Mind Flayer’s body is destroyed, the mall is left wrecked and burning, and the Russian base is shut down.