Season 4 of the series unfolds three interconnected plots across various settings. In Hawkins, cheerleader Chrissy Cunningham's untimely death places Eddie Mson under suspicion, pushing the Hawkins kids to clear his name. The group, including Dustin Henderson, Max Mayfield, and others, unveil Vecna as the true villain based on D&D lore. Eddie eludes a witch hunt to assist in defeating Vecna, sacrificing himself heroically.
In California, Mike Wheeler joins Eleven and friends on a mission to restore her powers. Through a secret isolation tank, Eleven regains strength, but faces past traumas. Her enhanced powers enable a mental connection with Max in Hawkins during the confrontation with Vecna.
Meanwhile, Joyce Buyers and Murray Balman venture to Russia to rescue Hopper from a prison camp, only to return to eliminate demogorgons, unknowingly aiding the fight against Vecna. These coordinated attacks ensure a temporary victory, but the looming threat of Vecna persists, hinting at challenges for the upcoming season.