In this story set in 4000 B.C.E. in what is now southeastern Europe, Naya is the 14-year-old daughter of Potis, the chief of her clan. She chafes against traditional rules, wishing for the freedom that the boys in her tribe are afforded. An encounter with a wild, red filly, which appears to telepathically communicate with her, secures the girl’s belief she’s meant for something more—but she must also convince her family. Her grandmother proclaims the quest Naya’s “soul journey,” but Potis is resistant, realizing that the horses could be a source of both great power and great danger. Naya tracks the herd through the grasslands, but just as she finds them, a young nomad named Aytal accidentally impales her with an arrow. Guilt-ridden, Aytal tends to Naya while his father, Oyuun, and younger brother race to find Naya’s clan. Eager to move the clan before winter, Potis agrees to let Aytal and Oyuun watch over the injured girl with the help of Naya’s mother, Sata; in exchange, Aytal’s brother remains with the clan as a hostage. The bulk of the story centers on Naya’s recovery and reconnection with the filly, Aytal’s sacrifices as atonement, and the forbidden feelings Sata and Oyuun start to have for each other. This impeccably detailed novel illuminates Naya’s journey on the ancient Pontic-Caspian steppe. Barnes skillfully develops key relationships in a manner that will make readers invested in the narrative. She also captures the tentativeness of romance and conflicts between traditions and other strong beliefs. As this is the first book of a planned series, some story elements are only hinted at—including a potential overthrow of Potis and Aytal’s punishment—and the book may have benefited from a bit more resolution. Also, the inclusion of 20 pages of supplemental material, showcasing the research that went into this book, seems overly extensive.