Contains spoilers for this episode and earlier episodes.
Nancy, Robin and Eddie rescue Steve from the bats, then seek weapons at the Upside Down's Wheeler house. Nancy finds that her guns are missing and her diary stops on the day Will disappeared in 1983. Hearing Dustin from the other world, they use light to make contact. Dustin and his friends arrange communication through a Lite-Brite and direct them to the gate in Eddie's trailer. Robin and Eddie climb through, but Vecna captures Nancy's mind before she can escape.
Joyce and Murray enter the prison with Yuri, with Murray impersonating the smuggler. The prisoners are released into the arena, where the Demogorgon kills the others as Hopper holds it back with fire. Murray overpowers the guards and Joyce opens an escape route, allowing Hopper and his fellow survivor to get away from the creature. Hopper finally finds Joyce waiting for him. In Nevada, Eleven returns to the memory of the laboratory massacre and follows the orderly's proposed escape route.
Eleven removes a device from the orderly's neck, restoring his powers. He reveals that he is One and kills the laboratory's children and staff. His account and Nancy's visions disclose that he is also Henry Creel, who murdered his mother and sister and left his father blamed for their deaths. Eleven refuses to join him. Drawing strength from a happy memory, she overpowers One and tears open a gateway that sends him into another realm. Lightning transforms him into Vecna.