The book is laid out as a step-by-step guide on how to clone an animal, with each chapter detailing a different topic that needs to be explored and answered before de-extinction of a species will be complete.

[5] Three following chapters discuss current technology available for moving genes and creating modified elephant genomes, including CRISPR (Clustered Regularly Interspersed Short Palindromic Repeats) and TALENS (Transcription Activator-like Effector Nucleases).

[9] Caspar Henderson for The Spectator called the book's writing "lively, skeptical and nuanced" and stated that Shapiro covered topics with "great clarity".

[13] A review in Publishers Weekly applauded the book's attempt to state plainly the science involved and determined that readers will "emerge with the ability to think more deeply about the facts of de-extinction and cloning at a time when hyperbolic and emotionally manipulative claims about such scientific breakthroughs are all too common".

[15] In The Quarterly Review of Biology, Derek D. Turner called the writing "careful, accessible, and thoughtful", while also pointing out that the book as a whole "conveys a sense of excitement about the science, but without the uncritical techno-optimism that one sees in many popular articles".