Now you have to live the rest of your life knowing you're going to die someday and disappear forever.
Jane Ives (or better known as Eleven or El for short) is a major character in Stranger Things. As a result of bizarre experiments by the CIA's Project MKUltra; of which her mother was a test subject; Ives was born with extraordinary psychic abilities, mostly manifesting in the form of telekinesis and some kinds of telepathy. At birth she was abducted and raised in Hawkins National Laboratory by Dr. Martin Brenner, who conducted further experiments and assigned her the subject number "011", hence her being referred to by that "name".
She can be seen entering the Oasis.