A Swiftly Tilting Planet by Madeleine L'Engle is about the quest to stop a South American dictator from initiating nuclear war. Charles Wallace, with the help of his older sister Meg, must travel through time and manipulate events by "going within" other people in order to prevent this disaster from happening. I found the whole "going within" thing interesting and a bit like Quantum Leap. I was also intrigued by how things from different time periods seemed to affect each other. I really love the protection spell that was used throughout the book and I've used it in my own prayers ever since the first time I read this book. The story was ok on the whole, but the main plot really didn't do much for me, though I recall enjoying the book a lot more when I was younger. I'd recommend this book if you enjoyed the first two books in the series, especially The Wind in the Door, as you get to see more of the deep spiritual connection between the characters that you saw in that book. This book takes place after Many Waters even though it was written first, but it's not necessary read the books in chronological order.