Maddie (Peyton List) is desperate for answers about her death after discovering that her body is possessed by Janet, a malevolent spirit. As she confronts Mr. Martin (Josh Zuckerman), her friends Charley, Wally, and Rhonda navigate their own challenges to escape the fallout shelter. Tensions rise as they uncover secrets from Mr. Martin's journals, leading Maddie to question her existence and whether she can reclaim her life.