Finn is a sixteen-year-old high school student with bright copper hair and large green eyes. She is observant and straightforward, yet deeply empathetic toward others. She frequently acts as a vital communicator within her highly conflicted family, eagerly anticipating an upcoming formal dance but dreading a mandatory family trip to Big Bear.

Mo is Finn's beautiful and charming best friend. Coming from a wealthier background with a highly protective mother, she wears designer clothes and takes exotic vacations. Despite the differences in their family dynamics, she is easygoing and fits seamlessly into the Miller family's chaotic orbit during their trip to the mountains.

Ann is the capable matriarch of the Miller family who works as a lawyer. She drives a brand-new Mercedes SUV and often projects a rigid exterior that masks her emotional struggles, particularly concerning her strained marriage to Jack and the demanding needs of her youngest son. She relies heavily on her close friendship with the Gold family for stability.

Jack is Finn's athletic father and a former yacht captain who sacrificed his career on the ocean to care for his son, Oz. He organizes the family ski trip to Big Bear in a desperate attempt to mend the growing fractures within his household. He connects easily with his children but remains deeply at odds with his wife.

Chloe is the eighteen-year-old middle daughter of the Miller family. She shares Finn's copper hair but projects a rebellious attitude, frequently clashing with her parents. She maintains a fiercely independent streak, heavily influenced by her college-aged boyfriend who joins them on the trip.

Oz is the thirteen-year-old youngest child of the Miller family. He has a developmental disability that leaves him with the emotional maturity of a toddler. His large physical size and quick temper often create significant tension within the family, leading his father to become his primary source of support.

Bob is a close family friend who acts like an uncle to Finn and her siblings. He travels with the Millers on their ski trip, displaying a confident, take-charge demeanor that occasionally masks a tendency to prioritize his own family's comfort over others.

Karen is Ann's long-time best friend, acting as an aunt figure to Finn. She is meticulous about her appearance and values order, bringing her husband and daughter along on the Millers' ski trip while maintaining a sharp focus on her own family's welfare.

Aubrey is the eldest Miller daughter, whose upcoming wedding serves as a rare point of unity for the fractured family. She shares many interests with her mother and manages to avoid the stressful family ski trip by visiting her fiancé's parents in Ohio instead.

Natalie is the only child of Bob and Karen Gold. Snobbish and highly competitive with Finn and Mo, she frequently attempts to assert her superiority, which tends to alienate the other girls during their shared vacation.

Vance is Chloe's college-aged boyfriend who tags along on the families' ski trip. He possesses an arrogant streak and heavily influences Chloe, sharing her rebellious nature while frequently pushing her to defy her parents' boundaries.

Kyle is a tall, good-looking stranded teenager whom Jack offers a ride to during the worsening blizzard. He quickly captivates the attention of the girls in the camper and proves to be a highly capable presence when the group encounters a severe emergency.

Mo's protective mother. She strictly guards her daughter's safety and only reluctantly entrusts Mo to the Miller family for the ski trip, possessing a sharp intuition about potential dangers.

A high school boy who acts as Finn's crush. He communicates with her through text messages just as the group heads up the mountain, providing Finn with a sense of normal teenage anticipation.

A competent sheriff's deputy and emergency responder who oversees search and rescue operations in the Big Bear area. He approaches his duties with a critical eye, striving to establish facts during severe crises.

Oz's loyal dog who accompanies the family on their fateful ski trip. He serves as Oz's primary source of comfort and emotional regulation during high-stress situations.

Aubrey's fiancé, whose parents she visits in Ohio while the rest of the Miller family travels to Big Bear. He represents a stable, happy future away from intense family conflicts.