S1E8 · Chapter Eight: The Upside Down

Complete story — includes the ending

Hopper, haunted by the death of his daughter Sara from cancer years earlier, gives up Eleven's location to Brenner, who in exchange allows Hopper and Joyce to enter the Upside Down to rescue Will. Nancy and Jonathan cut their hands to attract the Demogorgon at the Byers' house. Steve, intending to apologize to Jonathan about their fight, arrives just as the Demogorgon appears. Steve, Nancy, and Jonathan fight the Demogorgon and light it on fire, forcing it to retreat back into the Upside Down. Meanwhile, Eleven and the boys hide in the middle school when Brenner and his agents arrive to kidnap Eleven; she kills most of them before collapsing from exhaustion. As Brenner and his remaining agents pin Eleven and the boys down, the Demogorgon appears, attracted by the dead agents' blood, and attacks Brenner and the remaining agents as the boys escape with Eleven. Hopper and Joyce enter the Upside Down's version of the Hawkins library, where they encounter several corpses of the Demogorgon's victims, including Barb, and find Will unconscious with a tendril down his throat. Hopper revives him using CPR after removing the tendril. The Demogorgon corners the kids, but Eleven recovers from her exhaustion and disintegrates it, causing them both to disappear. Will recovers in the hospital, reuniting with his family and friends. One month later, it is Christmas and Nancy is back together with Steve, and both are friends with Jonathan. Will coughs up a slug-like creature and has a vision of the Upside Down, but hides this from his family.