When Marigold moves from California to the small Midwestern city of Cedarville with her newly blended family, nothing will ever be the same. Her mom's new job with the Sterling Foundation comes with a free house, a picture-perfect, historic house on Maple Street, and Mari has to share this house with her annoying ten-year-old stepsister, Piper. But when weird things start happening in the house and her concerns don't seem to be taken seriously by anyone else, Mari starts to wonder if it's all in her head or it has something to do with what's in their basement.