At the age of thirty-six, on the verge of completing a decade's training as a neurosurgeon, Paul Kalanithi was diagnosed with inoperable lung cancer. One day he was a doctor treating the dying, the next he was a patient struggling to live. This is the story of Kalanithi's transformation from a medical student in search of what makes a virtuous and meaningful life into a neurosurgeon working in the core of human identity - the brain - and finally into a patient and a new father.