Willa is a high school junior who recently relocated from Connecticut to a lavish Hollywood mansion at 2121 Sunbird Lane. Burdened by profound guilt over her father's sudden death, she conducts secret nightly rituals with a candle and a moldavite ring in an attempt to contact his spirit. She experiences recurring headaches and terrifying visions of a serial killer's victims, forcing her to question her own intuition and mental state while adjusting to the social hierarchy of Langhorn Academy.

Wyatt is a socially ostracized student at Langhorn Academy who becomes Willa's chemistry lab partner. He possesses a highly analytical mind and obsessively researches the local Hollywood Killer using a meticulous red notebook. His reliance on empirical data and blunt honesty initially alienates Willa, but his commitment to factual investigation makes him a valuable counterpart to her intuitive experiences.

Reed is a Langhorn Academy graduate who works as Jonathan Walters's assistant. He presents himself as a kind, relatable outsider who quickly forms a bond with Willa by validating her feelings of displacement in Los Angeles. He serves as a comforting presence in the mansion, connecting with Willa over their shared experiences of feeling like they do not quite belong in the glamorous Hollywood sphere.

Marnie is a cynical but friendly student at Langhorn Academy who takes Willa under her wing. As a self-described Hollywood kid, she moves through the competitive environment by constantly fabricating stories and crafting elaborate public personas. She freely lies to reporters and peers alike to gain social currency, illustrating the extreme lengths people go to for attention in the entertainment capital.

Jonathan is a wealthy, successful film director who recently married Joanna. He owns the historic mansion at 2121 Sunbird Lane and attempts to build a relationship with Willa by purchasing expensive gifts, such as a Gucci backpack and a new laptop. His extensive DVD collection and deep knowledge of classic cinema inform his professional life and the atmosphere of his home.

Joanna is Willa's mother, who recently moved the family from Connecticut to California. She embraces her new identity as the glamorous wife of a famous film director, dyeing her hair blonde and leaving her former career behind. She frequently worries about Willa's headaches and emotional isolation but remains shut out by her daughter's protective emotional walls.

Paige is a young film enthusiast who ran a blog documenting obscure cinematic history, including details about the actress Diana Del Mar and her unproduced screenplays. Her writing and research serve as a vital source of information for Willa and Wyatt as they investigate the mysterious events surrounding the mansion.

Leyta is a psychic known in Los Angeles as the "Psychic to the Stars." She possesses genuine intuitive abilities and helps clients understand spiritual phenomena. When consulted, she provides critical context about supernatural portals, spirit attachments, and the dangers of amateur occult practices.

Diana Del Mar is a 1930s Hollywood actress who formerly owned the mansion at 2121 Sunbird Lane. She famously died in the upstairs bathtub of the home, leaving behind a legacy of cinematic history and an unproduced screenplay that continues to cast a long shadow over the property decades later.

Paul is Willa's deceased father, who passed away following an argument at a swimming pool two years prior. He gifted Willa her old, rickety laptop, which she treasures over newer, expensive items. His memory heavily influences Willa's emotional state, driving her attempts to contact the afterlife.

Brianna is a young actress and the first known victim of the local serial murderer. Her final moments, which involve a traumatic captivity mirroring classic film scenes, are supernaturally broadcast to Willa.

Faith is the second victim of the serial murderer. Her captivity involves a wheelchair and a man wearing a rose charm necklace, details that provide crucial early clues regarding the perpetrator's violent methods and cinematic inspirations.

Lorelei, often referred to as "Lor," is another young victim of the Hollywood Killer. During her captivity, she is given a cheap imitation necklace by her captor, an interaction that highlights the dehumanizing and controlling nature of the crimes.