Forces of Nature explores the intersections of disability and loss, nature and nurture, families of origin and families of choice. It begins with the moment the author, Gina DeMillo Wagner, finds out her brother Alan, who had a complicated genetic disorder, is dead. From there, she takes readers along as she is pulled away from the safety of her friends, away from her husband and kids, and thrust back into a family she has been estranged from for nearly ten years. The memoir documents this rewinding and revisiting of the past, plus Alan’s Christmas-themed funeral, an investigation into Alan’s cause of death, Wagner's unraveling in the face of complicated grief, and finally the day –ten months later –when her parents divide his cremated remains and bury him in separate states. Within this framework, Wagner weaves in scenes from her childhood that illustrate what it’s like to be a sister and caregiver to a sibling with disabilities, the daughter of a mentally ill parent, and how she forges her own path and find peace by creating a family of choice.