the mysterious disappearance of Will Byers in Hawkins, Indiana (1983), leading his friends (Mike, Dustin, Lucas) to find a psychokinetic girl, Eleven (>>!Eleven<<), who escaped a government lab, while Will's mom (Joyce) and Police Chief Hopper uncover a government conspiracy involving a shadowy parallel dimension, the Upside Down<<, and a monster (Demogorgon) that took Will, culminating in Eleven closing the portal with Hopper's help and Will's return, though a piece of the monster remains.