While the boys are busy with physics, Nancy Wheeler and Jonathan Byers form an unlikely alliance born of shared grief and guilt. Their investigation leads them to the woods where Barb vanished.

In the episode’s final minutes, Nancy finds a literal hole in a tree. She crawls through, entering the Upside Down for the first time, only to come face-to-face with the Demogorgon while Jonathan is just feet away in the "real" world, unable to hear her. Why This Episode Matters for the Series

: Sheriff Hopper breaks into Hawkins National Laboratory and discovers the "gate"—a pulsating, organic fissure leading to another dimension. He is quickly knocked out and drugged by lab guards, waking up in his home surrounded by planted evidence of a "binge" to discredit his findings. The Rift in the Party

: Nancy discovers a portal in a tree and enters the Upside Down alone. She sees the Demogorgon