Lieutenant Bev Miller is an experienced Maine state game warden leading a complex multi-agency search for a missing hiker. As one of the few female game wardens in the state, she spends decades working twice as hard as her male counterparts to prove her capability. She throws herself entirely into her work, often neglecting her personal life and ignoring calls from her sisters regarding their mother, who is currently in hospice care. Tall and solitary since childhood, Bev feels a deep connection to the outdoors, finding a sense of belonging in the woods that she rarely experiences in traditional social settings.

Valerie is a 42-year-old nurse who takes a leave of absence to thru-hike the Appalachian Trail following the intense exhaustion of working through the COVID-19 pandemic. Using the childhood trail name "Sparrow," she is an empathetic, slow-paced hiker who naturally makes friends along her trek. Seeking an opportunity for self-reflection, she attempts to process her complicated feelings about her marriage while facing the harsh physical realities of the wilderness.

Lena is a 76-year-old resident of a Connecticut retirement community who uses a wheelchair. A former child prodigy with a brilliant scientific mind, she prefers reading and foraging for local plants over socializing in the community dining room. She lives an isolated life marked by deep regret over her estranged relationship with her daughter, substituting personal affection with clinical observation and online research.

Ruben is a Bronx-born son of Dominican immigrants who hikes the Appalachian Trail under the name "Santo." A large, self-described "fat" hiker, he is highly conscious of how others perceive him due to his size and race in the predominantly white hiking community. He forms a strong connection with Valerie on the trail because she accepts him without judgment, and they hike together until a family emergency forces him to return home.

Gregory is Valerie's husband, an anti-establishment individual who mistrusts authority and openly supports defunding the police. He facilitates Valerie's thru-hike by driving alongside the trail and meeting her at scheduled checkpoints to deliver essential supplies. His defensive, unorthodox behavior makes him an early suspect for the wardens, but he relies heavily on Valerie, who previously helped him achieve sobriety.

Operating primarily online under the handle "TerribleSilence," Daniel is a young man who matches Lena's deep knowledge of foraging and plant identification. He holds intense anti-government views, obsessing over a top-secret military training school located near the Appalachian Trail. He attempts to live entirely off the grid, frequently expressing frustration with organized society and its institutions.

Mike is a retired game warden with a loud personality and a tendency to tell outdated jokes. He maintains close ties with his former law enforcement colleagues and occasionally returns to the command center to assist during major operations. As an older officer, he distinguishes himself by treating female colleagues, particularly Bev, with genuine respect and equality.

Cody is a hardworking Maine game warden serving on Bev's search team. He is an empathetic officer who conducts field interviews, demonstrating a respectful and understanding approach when speaking with civilians about sensitive emotional topics.

Tanya is a female game warden serving on Bev's search-and-rescue team. Competent and thorough, she possesses strong interpersonal skills and emotional intelligence, allowing her to accurately assess the behavior and honesty of distressed family members during investigations.

Rob is Bev's second-in-command, a plainspoken local Mainer whose roots in the community lend the search team credibility. He is a grounded, kindhearted family man who previously lost an infant sibling, an experience that informs his quiet dedication to search-and-rescue work.

Warren is an extroverted resident at the assisted-living facility who harbors deep affection for Lena. He patiently accompanies her on foraging trips, acting as her physical proxy since she uses a wheelchair, and continuously tries to integrate her into the community's social life despite her obvious reluctance.

Christine is Lena's estranged daughter who eloped at age 18 and moved to Canada to become a nurse. Growing up as the subject of her mother's detached, scientific observation rather than experiencing traditional maternal warmth, she ultimately cut off contact to heal from her childhood.

Janet is Valerie's mother, sharing a striking physical resemblance with her daughter. She is a resilient, exactingly loving parent who maintains high hopes for Valerie's safe return and actively participates in the search effort by passing out flyers to the public.

Wayne is Valerie's father. He travels to the search headquarters to support the rescue efforts, sharing fond memories of his daughter's childhood with the wardens and expressing unwavering support for his son-in-law during a stressful period.