Includes bibliographical references (pages 305-367) and index.

A renowned biochemist reveals a scientific renaissance that is hiding in plain sight--the elusive Krebs cycle, the "perfect circle" at the heart of metabolism, discussing why it is still spinning at the heart of life and death today. Lane reveals the beautiful, violent world within our cells, where hydrogen atoms are stripped from the carbon skeletons of food and fed to the ravenous beast of oxygen. Yet this same cycle, spinning in reverse, also created the chemical building blocks that enabled the emergence of life on our planet. Now it does both. How can the same pathway create and destroy? What might our study of the Krebs cycle teach us about the mysteries of aging and the hardest problem of all, consciousness?