Carly is a 20-year-old college student who pauses her business studies to investigate the 1982 disappearance of her aunt. Using inheritance money left by her recently deceased mother, she relocates to the small town of Fell. She takes a job working the exact same night shift her aunt once worked at the Sun Down Motel. Carly approaches the paranormal and true crime elements of her search with logic and caution, relying on public records and local archives to gather facts.

Vivian is a 20-year-old from Illinois who ends up in Upstate New York after a frightening hitchhiking experience. Seeking independence from her family's expectations following her parents' divorce, she accepts a job as the night clerk at the Sun Down Motel. She rents an apartment in town and cuts her hair short to signify a fresh start. Her isolation leads her to eavesdrop on motel guests and investigate a string of unsolved local murders.

Nick is a 29-year-old man staying long-term at the Sun Down Motel in 2017. He carries deep trauma from his childhood, specifically an incident where his father shot and killed his older brother. The motel is the only place he can sleep peacefully. He keeps a gun on his nightstand for protection and assists Carly in understanding the supernatural events happening on the property.

Alma works as the only female police officer on the night shift in Fell during 1982. She faces discrimination in her department and is careful not to jeopardize her career without concrete evidence. By 2017, she is retired and lives in an old farmhouse with her dog. She acts as a bridge between the two timelines, holding institutional knowledge about the town's dark history.

Simon is a traveling salesman who frequents the Sun Down Motel in the early 1980s. He lives in a neat bungalow on Fairview Avenue with his wife and young daughter. He deliberately uses false names when signing the motel registry, behavior that catches the attention of the night clerk. His arrivals at the motel often coincide with aggressive paranormal activity.

Heather is a local college student studying medieval literature in 2017. She suffers from chronic back pain following a bicycle accident and self-medicates with prescription pills. Due to her intense fear of living alone, she invites Carly to move in with her. She is a dedicated true crime enthusiast who uses her local connections to help Carly research Fell's history.

Callum is a college student in 2017 who spends his free time in the local library's Archive Room. He claims his mother is a professor and he attends classes for free. He takes an immediate interest in Carly's research regarding the Sun Down Motel and frequently texts her links to old newspaper clippings. His intense focus on her investigation makes her increasingly uncomfortable.

Marnie is a photographer operating in Fell during 1982. She takes private freelance jobs, such as photographing cheating spouses for divorce lawyers. She captures images of the Sun Down Motel during her surveillance work and reluctantly gives Vivian a driving tour of the locations where several local women were found dead.

Betty is the ghost of a school teacher whose body was discovered during the construction of the Sun Down Motel in 1978. She appears to both Vivian and Carly as a woman in a floral dress. Her spirit is angry and highly active, possessing the ability to blow open locked doors, manipulate the motel's electricity, and directly warn the night clerks of danger.

Henry is a ghost who died of a heart attack in the motel office chair six months after a tragic accident occurred on the property. Known primarily as the smoking man, his presence is often announced by the strong smell of tobacco. He tends to observe the night clerks and guests from the parking lot.

Also referred to as Billy, he is the ghost of a nine-year-old boy who died after hitting his head on the concrete near the motel pool. He appears dressed in summer clothing. He is often confused about his current state and wanders the property complaining that he does not feel well.

Jenny lives with Vivian in 1982 out of schedule convenience. She desires to marry wealthy and leave Fell, but stays because she has steady employment as a nurse. In 2017, she still works at the Keenan Retirement Residence and provides Carly with insight into Vivian's moody demeanor prior to her disappearance.

Jamie is a frequent guest at the Sun Down Motel in 1982. He sells marijuana out of his rented rooms and flirts casually with Vivian at the front desk. He represents the kind of man Vivian's mother would expressly forbid her from bringing home, which increases his appeal to her.

Janice and her husband built and own the Sun Down Motel in 1982. She hires Vivian on the spot, offering her a free room in exchange for working the overnight shift so Janice can rest. She acts as a brief maternal figure, scolding Vivian for taking rides from strangers.

Chris is the son of the original motel owners. By 2017, he manages the property, which has fallen into severe disrepair and lacks modern amenities like Wi-Fi. He downplays the dangers of the night shift and avoids discussing the motel's dark history.

Graham is Carly's 23-year-old brother who remains in Illinois. He is engaged to be married and is deeply concerned about Carly abandoning her business degree. He serves as a voice of conventional expectation, urging Carly to return home and engage in normal family routines like Thanksgiving dinner.