Marty is an eleven-year-old boy living in a rural, working-class community in West Virginia. He takes his chores seriously and understands the financial limits of his household. Deeply sensitive to the pain of animals, he hopes to work as a veterinary assistant in the future. His strong internal moral compass frequently puts him at odds with the strict rules of his town.

Judd is a fast-talking, round-faced man who lives near the Preston family. He works his hunting dogs hard, keeping them lean and chained, and views them merely as tools rather than living creatures deserving affection. A scofflaw by nature, he routinely ignores hunting regulations and local laws. He carries unhealed wounds from a deeply abusive childhood.

Shiloh is a young, brown and white beagle with expressive eyes and a sweet disposition. He bears the physical and emotional scars of past abuse, making him unusually silent and fearful of loud noises. Despite his traumatic past, he remains eager for affection and responds quickly to kindness.

Lou is Marty's tough, practical mother who works hard to manage her family's tight budget. She takes on extra work from home and creatively stretches their resources, such as altering clothes so they last longer. Deeply attuned to her children's emotions, she immediately notices changes in Marty's routine and behavior.

Ray is a hardworking mail carrier who works two routes and takes on extra labor at home to support his family. He strongly believes in following the letter of the law and respecting the privacy of his neighbors. He is a pragmatic man who tries to ground Marty's idealism in the harsh realities of their rural community.

David is Marty's exuberant, sensitive classmate and best friend. He lives in a larger house with parents who hold professional jobs, giving him a more privileged lifestyle than the Preston family. Despite his size and slightly naive outlook, he remains emotionally open and is not ashamed to cry.

Becky is Marty's three-year-old sister. She shares Marty's sensitivity toward living creatures, showing empathy for bugs and animals. She brings a lighthearted presence to the household with her habit of giving people and pets butterfly kisses.

Dara Lynn is Marty's seven-year-old sister. She pesters her older brother by copying his actions and trying to follow him around. Unlike Marty, she possesses a slightly morbid curiosity and lacks his deep sensitivity toward wildlife, though she remains fiercely loyal to her siblings.

Doc Murphy is the round-bellied, kind-hearted local physician for the town of Friendly. Though he is not a veterinarian, he possesses the medical skills necessary to stitch up and treat animal injuries. He maintains a calm, professional demeanor while working within the tight-knit community.

Mr. Wallace is the shrewd, elderly storekeeper in Friendly. He observes the purchasing habits of the townspeople and quietly looks out for his neighbors. When he suspects a family is struggling financially, he utilizes the town's informal support network to help them.