In Stranger Things season 1, Joyce and Hopper find Will in the Upside Down version of the Hawkins Public Library basement, where he is unconscious and wrapped in vines.
Where Will Is Found
In the final rescue sequence of season 1, Joyce Byers and Chief Jim Hopper travel into the Upside Down through Hawkins Lab to search for Will. They eventually locate him in the basement area of the Upside Down Hawkins Public Library, not at his house or in the woods.
Will’s Condition When Found
When they reach him, Will is entangled in organic vines and connected by a tendril in his mouth, appearing pale and unresponsive. Hopper performs CPR to revive him, and they manage to bring him back from the Upside Down alive, though still affected by its influence.
