Claire is an elementary school teacher living in the suburbs with her husband and two children. Her marriage has soured since the birth of her daughter, leading her into a secret affair with her husband's best friend. She feels intense guilt over her deception but hesitates to end it. She remains fiercely protective of her female friends and struggles to maintain a pleasant facade during the group vacation.

Noah is a physicist who works from home. He is a pragmatic father whose lack of domestic involvement has caused a severe rift in his marriage. He frequently argues with his wife over minor household issues. Though logical and protective in dangerous situations, he struggles to communicate his emotions effectively under normal circumstances.

Jack runs his own contracting business and is Noah's former college roommate. In contrast to his highly educated friends, Jack is a free-spirited former musician. He possesses practical outdoor skills from his time as a Boy Scout and feels trapped in an unhappy marriage to a high-powered attorney. He seeks emotional refuge in a hidden romance.

Lindsay is a bubbly, physically fit former college roommate of Claire's. She is enthusiastic about her new relationship with a plastic surgeon and presents a loyal, energetic front to her friends. Her seemingly perfect exterior hides the quiet pressure she accepts from her new boyfriend's controlling habits.

Michelle is a successful divorce attorney. She is perceived by the rest of the group as intense and heavily focused on her career. She plans to work during the wilderness vacation and maintains a highly curated physical appearance. Her perfectionism makes her an intimidating presence to her peers.

Warner is a handsome plastic surgeon who recently began dating Lindsay. He is highly focused on physical fitness and frequently polices what his girlfriend eats, limiting her to salads and criticizing her body. His critical, demanding demeanor quickly isolates him from the rest of the vacationing group.

Emma is the young daughter of Claire and Noah. She is a sensitive child whose ominous dream about a monster eating her parents in the forest sets an uneasy psychological tone for the adults as they depart.

Aidan is the son of Claire and Noah. He is more independent than his sister and happily departs for his aunt's home while his parents leave for their wilderness retreat, managing his own basic tasks like laundry.

Penny is Claire's sister. She acts as a reliable support system for the family, taking care of Aidan and Emma so Claire and Noah can attempt to salvage their marriage on a group trip.