After her son Will (Noah Schnapp) goes missing, Joyce (Winona Ryder) is determined to find him by battling all odds. There are hardships aplenty, including some rather mysterious ones, which make some believe that Will is dead, but Joyce feels otherwise. She finds out about a secret lab and that leads her further. In her search, Joyce is joined by Eleven (Millie Bobby Brown) who had been held captive in the lab.