Robin is a nonmagical civil servant who recently inherited a baronetcy and an underfunded estate following the death of his narcissistic parents. An extroverted and highly observant man, he is thrust into a dangerous hidden world after being mistakenly assigned to the Office of Special Domestic Affairs and Complaints. He quickly becomes the target of a magical curse but remains fiercely protective of his sister and determined to handle his strange new reality.

Edwin is a highly intelligent, introverted magician who serves as the Magical Assembly's liaison to the government. Because he possesses minimal raw magical power in a society that values it above all else, he faces constant emotional abuse and marginalization from his aristocratic family. He compensates for his lack of innate strength with a deep, scholarly understanding of complex magical theory.

Walt is Edwin's older brother, a physically imposing and highly powerful magician who works in the family business. He epitomizes a masculinity rooted in violence and domination, taking obvious pleasure in using his superior strength to bully and belittle those he views as weaker.

Reggie is the original holder of Robin's civil service post who vanishes under mysterious and violent circumstances before the main events of the story. Like Edwin, he lived apart from a magical family that largely ignored him due to his lack of power, driving his desperate search for a way to acquire magic.

Maud is Robin's eighteen-year-old sister, a budding feminist who is eager to attend university now that her controlling parents are deceased. Resourceful and fiercely independent, she deeply loves her brother and relies on him to support her academic ambitions.

Miss Morrissey is a highly competent, biracial secretary in the Office of Special Domestic Affairs and Complaints. Despite lacking magic of her own, she hails from a powerful magical lineage and frequently deals with the sexist and racist assumptions of Edwardian society with sharp wit and efficiency.

Flora is Reggie Gatling's great-aunt and the formidable owner of Sutton Cottage. Outwardly appearing frail and unassuming, she actually possesses a deep, unconventional form of magic tied directly to her land, actively guarding dangerous secrets about the origins of British magic.

Jack, also known as Lord Hawthorn, is the son of an earl who lost his immense magical power following a devastating family tragedy. Bitter and openly cruel, he uses his considerable wealth and aristocratic status as a shield to mask the trauma of losing his magic and his twin sister.

Billy is a friendly and affable member of Edwin's social circle who, like Edwin, possesses very little innate magic. He masks his bitterness over his lack of power and past romantic rejections with a cheerful demeanor, frequently discussing theories of magical power transfer.

Belinda is Edwin's magically capable sister, who regularly hosts elite house parties at the family estate. She effortlessly conforms to the snobbish, hierarchical attitudes of her social circle and expects Edwin to prioritize their elite magical society over his nonmagical connections.

Charlie is Belinda's husband and Edwin's brother-in-law. A highly powerful magician, he frequently uses his raw power to create elaborate illusions for entertainment and is called upon to execute complex spells that require more force than Edwin possesses.

Kitty is Miss Morrissey's sister, a magical civil servant working within the exclusive headquarters of the Magical Assembly. She uses her access and abilities to discreetly assist her sister, working around the strict rules of magical bureaucracy with cleverness.

Miggs is a crude and highly privileged friend of Belinda and Charlie. He perfectly embodies the casual malice, elitism, and lack of empathy typical of their magical social circle.

Trudie is a pretty, wealthy socialite attending the gathering at Penhallick. She actively participates in the cruel gossip of the magical elite, frequently highlighting the personal tragedies or shortcomings of others for entertainment.

Anne is Reggie Gatling's sister. Entrenched in a family that values magical power above all else, she displays surprisingly little concern over her brother's sudden disappearance, viewing him as a disappointment.

George is a dangerous, ruthless magician seeking the components of the Last Contract. He is perfectly willing to use lethal force and terrible curses against anyone who stands in the way of his search for ultimate magical power.

Mrs. Courcey is Edwin's mother, who suffers from a severe form of arthritis. While she is somewhat kinder to Edwin than the rest of the family, she remains unable to truly protect him from her husband and older son's cruelty.

Mr. Courcey is Edwin's father, a severe man who views his son's lack of raw magical power as a personal tragedy and a shameful embarrassment to their ancient family lineage.

Elsie was Jack Alston's beloved twin sister, whose tragic death following a disastrous magical experiment haunts her brother and remains a popular subject of cruel gossip among the magical elite.