Seventeen-year-old Theo embarks on an unexpected adventure when her mother is asked to help chaperone college students at an archaeological dig site in Kenya. Although Theo begins the trip as a reluctant tagalong, she finds herself caught up in the excitement of what it would mean if the Chicago College Archaeology Crew actually finds what they’re searching for: a seven million-year-old skull belonging to the species that produced both chimpanzees and humans—the “missing link” in the evolutionary chain.

The discovery of the skull would be monumental. Because it has fangs for fighting but also an opening at the base for upright walking, it would provide physical proof of a last common ancestor between chimps and humans—and thus would offer decisive evidence of the theory of evolution by natural selection.

As Theo learns about the skull’s significance from the archeology team, she encounters the theory that evolution explains everything. But can that be true? She and her new Kenyan friend Wafula, whom Theo affectionately calls “Waffle” and who is rapidly becoming a love interest, explore various objections: What about morality, art, true love, free will, and the soul?

Because of the implications of its discovery, Theo’s crewmates are motivated to find the skull. Just how motivated becomes startlingly clear when one of the students is found dead—and Theo learns that it wasn’t an accident.

Now Theo and Waffle have new questions to investigate: What happened that would lead to murder? Did someone actually find the skull? And most importantly, who among the group is a murderer?

This intriguing and captivating story includes an “Explore More” section at the end that will guide readers to think more deeply about the concepts in the novel. It contains excerpts of important works written by twelve scientists, philosophers, and other thinkers who studied the topics debated in the novel, followed by discussion questions about those authors’ viewpoints. These questions will enable students to dig deeply into the issues, allowing them to consider not just various theories on the origin of the human species but also how we view ourselves in the bigger picture of all of life on Earth.