A girl and her younger brother go to live with their aunt (I think after their parents have an accident?). They aren’t fond of her. The book is in the girl’s perspective. The siblings go through some of their aunt’s things in her house (attic?). Somehow they are transported back in time to her childhood. They witness several events from her past. (I feel like I remember reading that when they are transported back in time, the sister is in the aunt’s body and the brother is in their father’s body. I may be wrong about that though.) Anyways I believe their grandfather was abusive towards the aunt and father in the past, so the aunt was protective of their father. I remember one of the last moments they traveled to was a peace rally, or an anti-war rally. (Think it may have been a protest against the Vietnam war- I remember mentions of peace signs.) I think by the end of the book they had grown to respect and appreciate their aunt more because of the experience.