Esme is a calm, practical 17-year-old returning to the summer camp she attended a decade ago. Beneath her composed exterior, she struggles with severe anxiety and guilt stemming from a tragic incident involving a fire during her childhood at the camp. As a counselor-in-training, she is fiercely protective of her young campers but becomes increasingly paranoid as threatening messages suggest someone knows her dark secret.

Kayla is Esme's bubbly, upbeat, and boy-crazy lifelong best friend. Having survived a childhood car accident that left her deeply afraid of physical danger, she masks her trauma with enthusiasm, pink clothing, and high heels. She aggressively denies the severity of their shared childhood secret, preferring to ignore the mounting threats at the camp in favor of pursuing a normal teenage summer.

Olly is a charming and somewhat mysterious counselor-in-training who claims to be from Missouri. He quickly takes an interest in Esme, pairing up with her for camp duties and initiating evening walks. While he presents himself as a supportive and capable staff member, he harbors secrets that complicate his budding romance with Esme.

Lillian is a ghostly figure from Esme and Kayla's past who was severely burned in a forest fire when the girls were children. Originally a traumatized runaway who tried to show the young girls something horrifying in the woods, she now exists primarily as a looming, unseen threat over Camp Pine Lake. Her memory drives the escalating paranoia as ominous signs begin appearing around the campgrounds.

Rebekah is a quiet counselor-in-training with a shy nature and a strong desire to please others. She confides in Esme about her history of being bullied, which makes her sympathetic but also socially isolated. Her anxious behavior, secretive phone calls, and unexplained burn scars quickly make her a subject of intense scrutiny as strange events plague the camp.

Andy is the strict lead counselor at Camp Pine Lake who demands order and adherence to routine. He is intensely focused on preserving the camp's reputation, which leads him to dismiss escalating threats, vandalism, and strange sightings as mere pranks. His refusal to contact the authorities or acknowledge real danger forces the teenage counselors to handle the camp's mysteries entirely on their own.

Jake is a confident, popular counselor-in-training who quickly catches Kayla's eye. He serves as a charismatic presence among the teenage staff, often participating in group activities and late-night excursions into the woods. Like Olly, he seems to know more about the surrounding area than he initially lets on, meeting the camp's strange occurrences with a mix of bravado and secrecy.

Tia is a bold and assertive counselor-in-training who brings energetic enthusiasm to the staff dynamic. She is open about her preference for dating girls but happily encourages her friends to mingle with the boys. She eagerly participates in the staff's rebellious late-night activities and social games.

Cora is an adult counselor at Camp Pine Lake who provides guidance to the younger counselors-in-training. She is practical and tries to maintain a cheerful facade for the campers, even when they get lost in the woods or encounter frightening situations. She serves as a reliable buffer between the anxious teenage staff and the oblivious children.

Ava is a young camper in Esme's group who is highly observant of her surroundings. Her innocent claims of seeing a mysterious figure lurking in the forest act as an early catalyst for the camp's creeping sense of dread, forcing the counselors to question whether the threats they feel are real or imagined.

Isabel is a nervous young camper who requires extra attention and encouragement from the staff to participate in outdoor activities. Her vocalized fears about the dark and the surrounding forest mirror Esme's own internal anxieties, highlighting the counselors' struggle to project safety when they themselves feel threatened.