(Warning: This post contains spoilers through Episode 8 of Stranger Things.) Stranger Things, the newest supernatural drama-thrill series from Netflix, is an awesome pastiche of Steven Spielberg '80s nostalgia. The first season has more than one reference to Spielberg's most famous movies, including E.T. the Extra-Terrestrial, The Goonies, Poltergeist, and Close Encounters of the Third Kind. Eleven, the mysterious and powerful young girl at the center of the mystery, is extremely reminiscent of E.T. – she loves Eggos the way America's favorite alien loves Reese's pieces – but, as we discover quickly, she is very much human despite having supernatural powers. But what are Eleven's powers on Stranger Things?
The near-mute little girl displays incredibly strong telekinetic abilities almost immediately. She appears first in Episode 1, turning up after the vanishing of Will Byers (the boy whose disappearance is at the center of the story). At first, I was totally convinced that she was an alien (all the E.T. references!) and that we were dealing with some kind of changeling-type situation, where human kid Will was swapped out (inadvertently or purposefully) with alien kid Eleven. But it quickly becomes clear that the monster that took Will is not an alien (in the colloquial sense, anyway), and neither is Eleven.
With gradually more illuminating flashbacks to Eleven's time with the Department of Energy, we discover that she is an empowered human child with telekinetic and psychic abilities – abilities that the super shady governmental agency (led by disappointingly cardboard cut-out villain Dr. Brenner, played by Matthew Modine) wanted to harness for their own use. It's the '80s, and via flashback we eventually see Dr. Brenner and his scientists immerse Eleven in a sensory deprivation tank in order for her to psychically "travel" across the world to spy on a Russian man, so it's heavily implied that their experiments were tied to Cold War-centric spying technology.
Eleven demonstrates her powers in several incredibly cool moments (like flipping over a van full of pursuing Department of Energy villains, using only her mind), but despite being considered a "superhero" by her new friends, El's backstory is actually quite tragic. Her past (and the nature/origin of her powers) is revealed in full in Episode 6.
When Chief Hopper and Joyce, Will's distraught mother, investigate the Department of Energy and the reports of the short-haired little girl spotted around town, they meet Terry Ives and her sister. Terry is an unresponsive woman whose brain was "fried" thanks to participating in a series of voluntary studies which involved her taking a series of drugs to "expand the boundaries of the mind," in exchange for pay. Tragically, as her sister explains to Hopper and Joyce, Terry was unknowingly pregnant at the time – with Eleven, who was originally named Jane by her mother. The experimentation somehow affected Eleven while she was in her mother's womb, resulting in her psychic and telekinetic powers.
The Department of Energy faked a miscarriage and stole Jane – marking her with an "11," implying that she was not the only powered baby resulting from the unethical experimentation – for their own nefarious purposes (i.e., spying on the Russians). Unfortunately, as far as I can tell, their sketchy uses for Eleven's powers inadvertently tear some kind of hole in between dimensions, allowing the "Demogorgon" to escape from the "Upside-Down," a dark, decaying alt-version of the real world, unleashing all kinds of death and destruction on the small town of Hawkins, Indiana – beginning with Will's disappearance.