Nathan is an eleven-year-old Navajo boy from Phoenix who struggles with his parents' recent divorce and insecurities about his weight. He possesses a strong aptitude for science, having won a blue ribbon at the Arizona Science and Engineering Fair. During his summer stay on the reservation, he discovers his unique ability to see and communicate with supernatural figures. He assumes the responsibility of healing a sick Holy Being to restore rain to the local desert.

Pond is the Water Monster of the Agave Pond, a Holy Being suffering from a decades-long sickness caused by radiation poisoning from the Church Rock Mine. His inability to sing his traditional songs has led to a severe regional drought. He carries deep sorrow over the animals that abandoned his dried-up home, yet he maintains a friendly and loyal disposition. He acts as Nathan's primary entry point into the supernatural world.

Nali is Nathan's paternal grandmother who lives in a mobile home lacking running water or electricity. She teaches the Navajo language to high school students and possesses deep wisdom regarding traditional beliefs. She carries immense worry for her family members, making tremendous personal sacrifices—including selling cherished heirlooms—to finance a healing ceremony for her troubled son.

Uncle Jet is a former Marine with an honorable discharge who struggles heavily with alcohol addiction and severe depression following the death of his father. His erratic behavior and dismissive attitude toward traditional medicine create constant tension in the household. Unbeknownst to his family initially, a hostile supernatural entity actively feeds his feelings of worthlessness.

The Ash Being is a vengeful entity created when a deceased person's spirit latches onto their killer. It acts as a parasitic force, whispering cruel lies and feeding on negative emotions. It directly exacerbates the despair and hopelessness of its hosts.

Devin is a Navajo medicine man and clan uncle who provides practical and spiritual guidance to Nathan's family. He lives in the mountains and approaches his work with a balanced perspective, acknowledging that ceremonies must sometimes be paired with modern medical therapy. He quickly validates Nathan's encounters with Holy Beings, offering the boy crucial encouragement.

Darkness is a powerful Holy Being credited with the invention of communication. He reads human character traits through magical sand paintings and acts as a demanding but supportive mentor to Nathan. He facilitates meetings between supernatural figures and grants Nathan a special stone to aid in his interactions with magical creatures.

Nathan's father lives in Phoenix and is navigating a new phase of life after his divorce. He struggles to understand his son's emotional needs and maintains a skeptical view toward traditional Navajo beliefs, dismissing them as fairy tales. He prefers to avoid conflict rather than confront difficult emotions directly.

Nathan's mother is an activist and documentarian whose long-term work assignment prompts Nathan's summer arrangements. Though physically absent from the main setting, her memory provides Nathan with emotional comfort during times of stress.

Leandra is the girlfriend of Nathan's father. Her presence in his father's life causes Nathan significant frustration, prompting the boy to invent a science project to avoid spending the summer with her.

Wind is a helpful Holy Being who assists Nathan in traversing the desert at night. He serves as an elemental ally during critical supernatural tasks and warns Nathan about the dangers of celestial locations.

Seed Collector is a grouchy horned toad who works as an assistant to First Turkey. He spends his time gathering untainted seeds in preparation for the inevitable ruin of the current world by humans. He initially views Nathan with intense suspicion.

Spider is a young arachnid who becomes an unlikely companion to Nathan. After Nathan protects his family by relocating them to a safe environment, Spider offers practical assistance during the boy's travels.

Andrea is the daughter of another patient undergoing the Enemy Way Ceremony. Because of her active belief in Navajo traditions, she possesses the rare ability to perceive Holy Beings, making her a comforting peer to Nathan.

First Turkey is a prominent Holy Being who diagnoses supernatural ailments. She organizes formal meetings to assess illness and formally issues the demanding tasks required to gather rare medicine.

Mother Water Monster is the fierce matriarch of the water monsters who resides in the watery domain of the Third World. She controls oceans and tides, demanding strict proof of peaceful intentions from any human visitors before offering assistance.