Hopper manages to elude the lab's stringent security measures and stumbles upon a mysterious portal tucked away in the bowels of the facility. However, his jubilation is cut short as the lab guards swiftly descend upon him, knocking him unconscious. He awakes at his home, groggy and disoriented, to find a hidden microphone planted in his midst.
His deputies arrive with unsettling news, informing him that Barb's abandoned car has been discovered. Hopper's suspicions are piqued by the state's involvement, sensing a deeper conspiracy at play.
Meanwhile, the boys deduce that Will has been trapped in an alternate realm, which Eleven ominously refers to as the "Upside Down." They realize he is being hunted by a monster, resembling a fearsome Demogorgon. Following Will's funeral, they seek guidance from their science teacher, Mr. Clarke, about alternative dimensions.
Mr. Clarke explains that a high-energy spacetime tear could theoretically create a bridge between dimensions, causing a disruption in the Earth's electromagnetic field. Armed with this knowledge, the gang heads into the woods, armed with compasses, to search for such a disruption.
Eleven, haunted by memories of encountering the creature during a lab experiment, panics and inadvertently misdirects the compasses. Lucas notices her hesitation and confronts her, leading to a tense confrontation. Mike jumps to her defense, and the two boys engage in a heated altercation. In the midst of the scuffle, Eleven lashes out telekinetically, sending Lucas flying off Mike.
As Dustin and Mike rush to the aid of the unconscious Lucas, Eleven flees, leaving them bewildered.
Lonnie returns to the town, ostensibly to offer comfort to Joyce over Will's disappearance. The two seem to reconcile, but Joyce's suspicions are triggered when she discovers that Lonnie's concern for his sons is merely a ruse. His true intentions are revealed when she catches him plotting a wrongful death lawsuit, capitalizing on Will's demise. Angered by his duplicity, she demands that he leave once again.
Elsewhere, in the depths of the woods, Nancy and Jonathan stumble upon a wounded deer. As the creature drags the deer away, Nancy follows the trail of blood, leading her to a portal that opens a gateway to the Upside Down. She cautiously crawls through, only to find the monster feasting on the helpless deer. She snaps a twig, drawing the creature's attention. Meanwhile, unaware of the closing portal, Jonathan frantically searches for Nancy in the forest...
