The book is structured as a series of letters from people in all walks of life—including students, prisoners, and priests—followed by Tyson's succinct and passionate replies.

: He offers reflections on mortality, describing death as a natural part of the cosmic cycle and noting that being born is a statistical improbability that makes life precious. Structure and Content Highlights

: The collection includes his defense of reclassifying Pluto as a dwarf planet and his responses to skepticism regarding climate change and evolution.