She has come here to die. When Lois Grover moves into the Beacon of Hope Assisted Living Center, she fears boredom will consume her, but a fellow resident soon invites her to a secret meeting of the Twilight Society. This quirky group of elderly residents, with a variety of skills, talents, and expertise, helps lost souls, tethered to the world of the living, by solving the mysteries keeping them from moving on. The center itself—a historic colonial mansion that has functioned as a hospital, a school, and a sanitarium—possesses mysteries of its own that both help and hinder the society's investigations. As Lois joins them on their latest case—a decades-old unsolved murder—she realizes that her new purpose may be more meaningful than she ever imagined.