This is a book that deals with the relationship between Christianity and romantic love, and features Williams' unique voice on the subject. It is about how romantic love and Christianity fit together. It illuminates a lot of things about both, and about forgiveness, particularily in the doctrine of Christ's substitution and the importance of our forgiveness of others' sins too, including the most heinous ones, like those of Hitler (this book was written in the middle of World War 2). In this book as well as Descent into Hell, Williams writes about romantic love in ways that make you see the experience of falling in love in a wholly other way.