Abby is an imaginative, determined sixteen-year-old high school student who attends a religious private school in Charleston on scholarship. Highly loyal and occasionally self-conscious about her family's lower socioeconomic status compared to her peers, she values her deep bond with her best friend Gretchen above all else. She relies on late-night phone calls, shared secrets, and a mutual love of 1980s pop culture to survive adolescence.

Gretchen is a wealthy, studious teenager living in a racially segregated, affluent neighborhood in Charleston. Raised by strict, image-conscious conservative parents, she often feels stifled by their severe household rules but finds freedom and an unbreakable bond in her friendship with Abby. After an incident following a party, she begins exhibiting troubling behavior that isolates her from her peers.

Andras is a malicious, supernatural entity tied to a historical outbuilding near the Middleton family lake house. Associated with owls and violence, he targets individuals by isolating them from their loved ones, sowing discord, and manipulating insecurities. He views human bonds as vulnerabilities to exploit.

Abby's parents face significant financial hardship due to job losses and a shift to lower-paying work. Mr. Rivers attempts to run a lawnmower-repair business from their yard, while Mrs. Rivers works exhausting shifts as an in-home nurse. Their financial insecurity makes them highly protective of Abby's scholarship, though the stress often causes them to seem detached from her teenage struggles.

Gretchen's parents are wealthy, conservative Republicans who are highly invested in their public reputation and social standing. They enforce severe rules on their daughter, forbidding rock music and monitoring her media intake. They are quick to place blame on outside influences whenever issues arise to protect their family's flawless image.

Margaret is an affluent high school sophomore whose family owns a polo plantation and a lake house. Despite her superficial confidence and immense wealth, she battles severe self-esteem and body image issues, heavily restricting her diet in an effort to lose weight. She is often quick to judge others and holds considerable social sway within the girls' friend group.

Glee is the quietest member of Abby and Gretchen's close-knit friend group. She tends to avoid conflict but can be highly impulsive when her emotions are triggered. She harbors an intense, secret crush on the school's young chaplain, which heavily influences her actions and distracts her from the shifting dynamics among her friends.

Christian is the youngest of the Lemon brothers, a traveling group of Christian bodybuilders who perform feats of strength at youth assemblies. Despite his muscular physique and theatrical public persona, he claims to possess a unique spiritual sight. He becomes an unexpected source of advice and support for Abby when he notices something deeply wrong with Gretchen.

Tommy is an older boy from Abby's childhood who accidentally causes her to get stitches during a roller-skating collision. He apologizes by giving her a cold can of Coke for the pain, an act of kindness that makes a lasting impression on Abby and becomes a treasured symbol of their shared youth.

Wallace is Margaret's arrogant, boundary-pushing boyfriend who plays on the high school football team. He frequently harasses Abby and Gretchen, acts inappropriately, and uses his social standing as an athlete to avoid consequences for his heavy drinking and aggressive behavior.

Father Morgan is the young, somewhat naive chaplain and ethics teacher at Albermarle Academy. Because of his youth, students often struggle to take his religious authority seriously, though his presence catches the romantic attention of students like Glee. He attempts to offer logical, psychological explanations for spiritual crises.

Riley is Margaret's older brother, a drug dealer with a dark, predatory history that his wealthy family has legally swept under the rug. He haunts the edges of the girls' social sphere, representing the real-world dangers and unchecked privilege that permeate their Charleston community.

Dr. Bennett is the irritable next-door neighbor of the Lang family. He frequently clashes with Mr. Lang over property boundaries and neighborhood nuisances, quickly escalating minor inconveniences into hostile, physical confrontations.

Andy is a boy from Florida whom Gretchen claims to have met at a summer Bible camp. He becomes Gretchen's confidant during her periods of severe distress, offering her advice on her frightening hallucinations over the phone and validating her worsening symptoms.

Principal Major is the strict head of Albermarle Academy. He is highly protective of the school's reputation and often bows to the pressure of wealthy, influential parents, which affects his disciplinary decisions regarding scholarship students like Abby.

Coach Greene is the volleyball coach at Albermarle Academy. She delivers stark, victim-blaming warnings to the female students regarding their reputations and physical safety, reflecting the problematic attitudes toward young women in their community.

Max is the Lang family's energetic pet dog. He frequently causes neighborhood disputes by getting into Dr. Bennett's garbage, but he shows genuine affection for Abby when she visits the house.