Pax is a fox who now lives fully in the wild, having been separated from his human companion a year prior. He steps into a new phase of life as he and his mate prepare to welcome a litter of kits. Raised by a human, Pax possesses a unique perspective on the world, balancing his wild instincts with a lingering trust in people. He acts as a dedicated father, carefully assessing dangers to keep his growing family safe.

Peter is a 13-year-old boy dealing with intense grief after the deaths of his parents and his forced separation from his pet fox. He lives with a veteran named Vola but actively pushes away emotional connections, believing that isolation will protect him from further pain. Seeking purpose and distraction, he joins a group called the Junior Water Warriors to clean up environmentally damaged rivers.

Vola is an older military veteran and librarian who has taken Peter in to live with her. She observes Peter's emotional withdrawal with concern, offering to give him a permanent piece of her property to ensure he always has a home. She acts as a patient but firm guardian, understanding the boy's grief while gently pushing him to let light and air into his life.

Sliver is the sole female kit in Pax and Bristle's litter. She exhibits a strong adventurous streak and frequently disobeys her mother to explore the world outside her den. Following a frightening encounter with an owl, she becomes more cautious but remains deeply attached to her father, insisting on following him when he travels.

Bristle is a wild vixen who serves as Pax's mate. She bears physical and emotional scars from the recent war, including a burnt tail and a deep-seated fear of humans after losing her family to their violence. She is a protective and cautious mother who relies on Pax to balance her anxieties about the outside world.

Jade is a 19- or 20-year-old volunteer with the Water Warriors, working to restore rivers damaged by the war. She wears a flowered scarf in her hair and approaches nature with a deep sense of wonder and observation. Kind, observant, and direct, she acts as a grounding presence for her partner Samuel and a gentle challenger to Peter's emotional isolation.

Samuel is a 19- or 20-year-old Water Warrior and military veteran who joins the environmental group to find purpose and community after losing his brother in the war. He sports a freshly shaved head and a neck tattoo. Unlike the expressive Jade, Samuel is straightforward, quiet, and treats his words carefully.

Peter's grandfather is a gruff, military-minded man who views the Water Warriors with skepticism. Despite his rough exterior and tendency to criticize, he demonstrates a quiet protectiveness over his grandson, offering survival advice and eventually signing the permission slip Peter needs to join the environmental volunteers.

Peter's deceased father casts a long shadow over the boy's life. Having died during the recent war, his ashes are carried in Peter's backpack as a heavy, physical reminder of loss. His past decisions heavily influence Peter's current understanding of grief and responsibility.

Peter's deceased mother lives on only in the memories of her son. She died in a car crash when Peter was eight years old, an event that profoundly altered the trajectory of his family's life. Her passing prompted her husband to burn all her belongings in an attempt to erase the pain of her absence.

Runt is Bristle's brother, a wild fox who lost a hind leg to human violence during the war. He remains close to his sister and her new mate, Pax. He checks in on the growing family and assists Pax in foraging for food when the kits require extra care.

Ben is one of Peter's friends from his old life. He stays close to home to support his younger sister during her upcoming medical operation. His dedication to his family serves as a sharp contrast to Peter's philosophy of avoiding emotional attachments.

Astrid is Ben's little sister. She is facing an upcoming medical operation, prompting her brother to stay close by her side rather than traveling.

Private Thomas Roberts is a soldier who served in the same unit as Peter's father. As an expectant father of twins, his situation deeply impacted Peter's father. Roberts's correspondence provides crucial context about the final days of the war and the circumstances surrounding his friend's service.