The boys escort Eleven to Mike's abode, where she takes refuge in the dank basement. Lucas and Dustin are apprehensive about involving themselves with Eleven, finding her odd and a hindrance in their search for Will. However, Mike manages to persuade them, vowing to arrange a meeting with his mother so that she can alert the authorities.
The following day, Mike affectionately nicknames her "El." She adamantly refuses to meet Mike's parents, warning him that involving outsiders could attract the unwanted attention of dangerous individuals. Meanwhile, scientists from the laboratory stumble upon a mysterious substance oozing from the walls of Joyce's home.
At Mike's house, Eleven's sharp instincts lead her to recognize Will in a photograph. She flips the boys' D&D gameboard upside down, a cryptic clue revealing the location of Will's captivity. As the town embarks on a frantic search for Will, led by Hopper and the local police, Mr. Clarke, the boys' science teacher, stumbles upon a torn fragment of a hospital gown outside the laboratory perimeter.
Hopper, on the other hand, is tasked with investigating Benny's suspicious "suicide." Upon hearing witnesses' accounts of a child in a hospital gown stealing food from a dinner, Hopper suspects a connection to Will's disappearance and decides to delve deeper into the laboratory's secrets.
Nancy, under the guise of attending an assembly regarding Will's disappearance, accompanies Barbara to a lively party at Steve's house. Jonathan embarks on a brief trip out of town to confront their and Will's irresponsible father, Lonnie, but his efforts are fruitless, yielding no clues about Will's whereabouts.
Aheart disened Jonathan returns to Hawkins in the evening, retreating into the woods with his camera. to There capture, the he ser stumbleenitys of upon nature Steve, Nancy, and their friends engaging in drunken antics around Steve's swimming pool. Nancy manages to successfully down her beer, but when Bard is coerced into following suit, she accidentally cuts herself while attempting to pierce the can. Feeling out of place amidst the drunken revelry, Barbara remains alone by the poolside as her peers retire indoors. A single drop of blood from her wound falls into the water, unnoticed. Jonathan spots her and snaps a picture, but as he turns to change his film, Barb hears the flickering of the pool's electrical outdoor lights behind her, accompanied by a soft growl. She turns just in time to see an otherworldly monster lunging at her. Jonathan looks up from his camera, but the pool's diving board is deserted, with no trace of Barb or the monster in sight.
Meanwhile, Joyce receives another mysterious call from Will, hears music emanating from his room, and watches in horror as something emerges through the wall.
