The series finale of "Stranger Things" left the fate of Eleven ambiguous after she seemingly sacrificed herself to defeat Vecna and the Mind Flayer. However, an 18-month time jump reveals Mike telling his friends a story that Eleven faked her death and is living a peaceful life near waterfalls, a place she and Mike had discussed earlier in the season. Creators Matt and Ross Duffer explained this open ending was a deliberate choice to explore the reality of Eleven's situation and the possibility of her living a normal life.
They presented two potential paths for Eleven: a pessimistic one or an optimistic, hopeful one, with Mike embodying the latter by choosing to believe in the fabricated story. The Duffer Brothers stated there was never a version of the ending where Eleven remained with the group, as they didn't want to take away her powers, which represent magic and childhood. For the story of Hawkins and the Upside Down to conclude, Eleven had to depart, and the creators felt it was more powerful for the characters to believe in a happy ending, even without confirmation. This approach allows for closure of the characters' journeys from children to adults, with the understanding that if Eleven is alive, the best the others can hope for is belief, as direct contact would unravel everything. This narrative choice serves to keep her "alive" and helps Mike and the others move forward. Millie Bobby Brown had previously shared on "The Tonight Show" that she discovered Eleven's ending by "sneaking into the writers' room" before the final table read, and the cast reacted with prolonged crying upon processing the various potential endings.