Contains spoilers for this episode and earlier episodes.
Unable to reach Hawkins in time, Eleven uses a saltwater tank in a pizza shop to enter Max's mind. Max draws Vecna to her at the Creel house while Lucas watches over her. In the Upside Down, Eddie plays 'Master of Puppets' to lure the bats away from Nancy, Steve and Robin. Hopper, Joyce and Murray return to the Russian prison to attack the creatures connected to the same hive mind, hoping to help their friends from a distance.
Jason confronts Lucas and demands that he wake Max. Their fight destroys her music player. Vecna overwhelms Eleven inside Max's mind and reveals how he shaped the shadow particles into the Mind Flayer. Mike tells Eleven he loves her and urges her to fight. Meanwhile, Eddie abandons his escape to keep the bats occupied and is fatally wounded. Murray burns the prison creatures, and Hopper beheads the Demogorgon. Freed from the vines holding them, Steve and Robin set Vecna alight while Nancy shoots him out of the attic.
Max's limbs break, and her heart stops, completing Vecna's fourth kill. Gates tear through Hawkins and kill Jason. Eleven restarts Max's heart, but two days later Max remains unconscious in hospital, unreachable when Eleven tries to find her mind. Dustin tells Wayne that Eddie died protecting the town, although residents still blame Hellfire for the disaster. The separated families reunite, including Hopper and Eleven at the cabin. Will can still sense Vecna, wounded but alive. Their reunion gives way to falling particles, red lightning and dying plants as the Upside Down begins spreading into Hawkins.