Stevie is a sixteen-year-old true-crime enthusiast beginning her first year at Ellingham Academy. She idolizes fictional detectives like Sherlock Holmes and Hercule Poirot, frequently using their stories to cope with her severe panic attacks and anxiety. Her primary goal in attending the academy is to solve the infamous cold case of the 1936 Ellingham kidnappings. She struggles to connect with her parents, who do not understand her unique interests or her need for independence.

Albert is an incredibly wealthy American tycoon who built his fortune from nothing. Following the Great Depression, he uses his wealth to create Ellingham Academy, a free school designed to celebrate learning and innovation. He possesses a deep love for games and puzzles, treating education itself as a playful challenge. His idyllic mountain retreat is shattered when criminals target his family.

David is a second-year student who designs video games. He intentionally dresses in shabby clothing, though expensive accessories like his Rolex watch hint at a wealthier background. He is charming and evasive, frequently deflecting questions about his family with contradictory stories about his parents.

Hayes is an attractive second-year student who recently achieved online fame through a zombie apocalypse web series. He actively leverages his good looks and deep voice to manipulate others into doing his academic and creative work for him. He focuses heavily on securing a Hollywood movie deal and maintaining his public image.

Iris is a wealthy socialite and the wife of Albert Ellingham. Accustomed to the busy social scene of New York, she sometimes finds life at the isolated Vermont mountain estate restricting. She is kidnapped along with her young daughter, setting off the central historical mystery of the academy.

Alice is the three-year-old daughter of Albert and Iris Ellingham. She represents the sole heir to the Ellingham fortune and is the center of her father's world.

Dottie is a bright fourteen-year-old student from New York City. She is invited to join the inaugural class at Ellingham Academy during the Great Depression. A voracious reader of detective fiction, she frequently explores the secret tunnels and hidden rooms of the sprawling campus.

Nate is an antisocial first-year student and a successfully published author. He currently suffers from severe writer's block while trying to produce a mandated sequel to his book. He dislikes social events but pushes himself outside his comfort zone to support his peers.

Janelle is a brilliant first-year engineering student with a cheerful demeanor. She quickly establishes herself as a warm and supportive presence in the dorm. She focuses her time on building machines and navigating the complex social dynamics of the academy.

Ellie is an eccentric, free-spirited second-year artist who grew up in various art colonies and communes. She openly flouts academy rules and takes pride in her rebellious nature. She is highly attached to her saxophone, which she affectionately calls Roota.

Robert is the faithful clerk and secretary to Albert Ellingham during the 1930s. He is highly practical and frequently urges his boss to take threats seriously, acting as a grounded counterweight to Albert's whimsical nature.

George is a former detective and current FBI agent who operates in the 1930s timeline. He is fiercely loyal to Albert Ellingham after the tycoon previously saved his life during a car bombing.

Flora is a former speakeasy hostess who befriended Iris Ellingham. Because of her lower-class background, she faces suspicion from investigators. She harbors secrets about Iris's private life but remains fiercely protective of her friend's memory.

Dr. Nell Pixwell, commonly known as Pix, is a bioarcheology specialist and the faculty housemaster for Minerva. She sets the ground rules for the incoming students and monitors their behavior.

Larry is the head of security at Ellingham Academy and a former detective. He takes the safety of the students very seriously and frequently patrols the isolated mountain campus.

Charles is a faculty adviser at Ellingham Academy. He grants students access to the school's historical archives but insists they remember the human cost behind famous tragedies.

Gretchen is a student at Ellingham who harbors deep anger over financial debts and manipulative behavior she endured in a past relationship.

Leonard is a chemist hired to teach art at Ellingham's school. He possesses specialized skills, including the ability to manufacture invisible ink for marking ransom money.

Agent Arnold is the federal investigator tasked with solving the Ellingham kidnappings. He probes into the backgrounds and secrets of the estate's guests.

Anton is a local anarchist who views wealthy industrialists as tyrants. He operates in the Vermont area and becomes a prime suspect in the ransom plot.

Edward is a powerful, radical-thinking politician known for pushing fascist ideas. His political influence casts a long shadow over those employed by his organization.

Maris is a first-year opera student at Ellingham Academy. She agrees to help procure costumes and build set pieces for a student film production.

Dash is a tech-savvy student who provides logistical and equipment support for campus media projects.

Germaine is a driven student journalist who runs the academy's premier news source, eagerly documenting campus drama and taking exclusive photos.

Kyoko is the librarian at Ellingham Academy, tasked with preserving the school's historical texts and fulfilling student research requests.

Detective Agiter is a modern investigator assigned to Ellingham Academy when tragedy strikes. She carefully probes the students for technical details regarding their recent activities.

Vi is a student at Ellingham Academy who quickly strikes up a connection with Janelle during the first social events of the year.

Beth is a YouTube star who maintains a casual, non-exclusive romantic arrangement with Hayes Major.