S5E4 · Chapter Four: Sorcerer

Complete story — includes the ending

Hopper and Eleven infiltrate the military base, intending to kill Henry. They defeat Dr. Kay and her soldiers, discovering that the captive inside is Eleven's adoptive sister, Kali. Max explains to Holly that they are trapped inside a psychic realm made of Henry's memories, nicknamed " Camazotz " by Holly, where Max has remained ever since her brief death. Will's group is attacked by a Demogorgon until Dustin, Steve, Nancy, and Jonathan chase it into the Upside Down. Meanwhile, the military detains children in Hawkins who could be potential victims. Will experiences a vision of Holly and three other children being restrained by tentacles in Vecna's lair, with empty spots for eight more. Will's group infiltrates the base to smuggle the children out of Hawkins. However, Henry, in his Vecna form, and three Demogorgons emerge from the Upside Down, slaughter most of the soldiers at the Hawkins base, and kidnap Henry's targets, including Derek. Before retreating into the Upside Down, Henry tells Will that he intends to use the children, whom he calls "perfect vessels", to reshape the world. Will then unlocks psychic abilities and kills the Demogorgons to save Mike, Lucas, and Robin.