: Focusing on aging and mortality.

: The book explores human existence, evolution, and the traces of prehistory that still exist in our modern lives. Collaborative Style

The "story" of the book is a series of excursions taken by the two authors over several months.

: They visit various locations ranging from common daily scenes like markets and parks to unique archaeological sites. These visits serve as a backdrop for Arsuaga to explain why we are the way we are and how our species evolved.