One of the biggest mysteries the inaugural season of Stranger Things left as a cliffhanger is what actually happened to Eleven (Millie Bobby Brown). Everyone's favorite Eggo waffle-loving psychic girl won the hearts of not just fans but of Mike Wheeler (Finn Wolfhard). Mike and his friends all watched Eleven confront the Demogorgon in a classroom at Hawkins Middle School and use her psychic powers to render it and herself into some sort of black ash. Of course, Eleven didn't die - we know she's a huge part of Stranger Things 2. The new season doesn't waste time revealing what happened to Eleven.
After destroying the Demogorgon, Eleven awoke in the Upside Down version of Hawkins Middle School. She soon found the hole in the wall the Demogorgon used to breach dimensions when it attacked and killed her ersatz 'papa' Dr. Martin Brenner (Matthew Modine). After evading some soldiers from Hawkins Laboratory, Eleven used her powers to widen the breach and she crawled through back to our world. Her first instinct was to go to Mike, but she saw Federal agents at the Wheeler home laying down a cover story that Eleven was a Russian girl and part of a Communist plot. Realizing she couldn't go home to the Wheelers, a frightened Eleven hid in the woods evading search parties.
After she used her powers on a local hunter and took his coat and hat, Eleven found the wooden box in the woods where Sheriff Hopper (David Harbour) left her wrapped Eggo waffles at the end of season 1. Soon, she meets Hopper in the woods and he takes her in, hiding her in his grandfather's shack in the woods - a new home, such as it is, for a girl who desperately needs one. Together, Hopper and Eleven clean up the shack and make it livable; Hopper even opens up his old vinyl collection and introduces her to Jim Croce's song "You Don't Mess Around With Jim" while they work.
Hopper, who still mourns for his own daughter who died, dedicates himself to keeping Eleven safe and does his best to be a father to her, though his meal preparation skills (TV dinners and more Eggo waffles) leave a lot to be desired. Hopper lays down three rules for Eleven to live by and their mantra is that she will stay safe if she's "not stupid." Eleven is able to use her psychic powers to visit Mike, who misses her and talks to her via his walkie-talkie in the little tent he made for her in the Wheelers' basement, but she wants to see Mike in person. Hopper won't allow it; he keeps promising that she will be able to see Mike "soon" but by the time season 2 begins, nearly an entire year has gone by and Eleven has grown understandably restless and impatient with cabin fever.
Eleven's survival remains a secret to everyone besides Hopper when Stranger Things 2 begins, but as he hears more and more reports of a "mysterious Russian girl" who is occasionally sighted by the people of Hawkins, Hopper suspects Eleven hasn't been adhering to Rule 3 like she promised. This sets the stage for the drama and intrigue that results for Eleven as she tries to reunite with Mike and we learn more about her origins in Stranger Things 2.
Stranger Things 2 is now streaming on Netflix.