Some books start at point A, take you by the hand, and carefully walk you to point B, and on and on.

This is not one of those books. This book is about mood, and how it works in and with us as complicated, imperfectly self-knowing beings existing in a world that impinges and infringes on us, but also regularly suffuses us with beauty and joy and wonder. You don't write that book as a linear progression--you write it as a living, breathing, richly associative, and, crucially, active, investigation. Or at least you do if you're as smart and inventive as Mary Cappello.

What...