Hazel is a brilliant 17-year-old noblewoman living in 1817 Scotland who aspires to be a surgeon. Driven by the tragic death of her older brother to the Roman fever, she possesses an unwavering passion for science and anatomy. Though she enjoys the privileges of her upper-class background, she actively resists the societal expectations that demand she prioritize marriage over medicine.

Jack is a 17-year-old resurrection man who digs up freshly buried bodies to sell to anatomists. Having survived homelessness and a difficult childhood, he maintains a surprisingly hopeful outlook on life. He works multiple jobs to survive, including stagehand duties at the Le Grand Leon theater, and relies on his practical street sense to stay safe in a dangerous profession.

Dr. Beecham is a charismatic, highly acclaimed surgeon in Edinburgh known for his showmanship and medical advancements. Claiming to be the grandson of the famous founder of the Royal Edinburgh Anatomists’ Society, he commands deep respect from his students. He views surgery as an elite science and conducts his lessons with a focus on rigorous, unflinching anatomical study.

Bernard is Hazel’s cousin and intended future husband. As a wealthy young nobleman poised to inherit the title of viscount, he is highly conscious of social status and appearances. He expects his life to proceed comfortably according to the established rules of Edinburgh's high society, viewing Hazel's scientific interests as inappropriate for a future noblewoman.

Dr. Straine is a pragmatic and bitter surgeon who assists Dr. Beecham by conducting anatomical demonstrations and purchasing cadavers. Wearing an eyepatch and a bloodstained coat, he cuts an intimidating figure. He harbors deep resentment toward the wealthy and strictly enforces the societal rules that bar women from the medical profession.

Lady Sinnett is Hazel’s grieving mother. Deeply affected by the loss of her eldest son to the Roman fever, she focuses her remaining energy on spoiling her youngest child and ensuring Hazel secures an advantageous marriage. She pays little attention to Hazel's intellectual pursuits, viewing them as eccentricities that threaten her daughter's social standing.

Percy is Hazel's seven-year-old brother and the heir to the family's wealth and title. Spoiled by his grieving mother, his health and safety are the household's absolute top priorities, especially when rumors of the plague return to Edinburgh.

George is Hazel's late older brother. His death from the Roman fever deeply fractured his family and serves as the primary catalyst for Hazel's intense drive to study medicine. Hazel regularly uses his leftover clothing to disguise herself as a young man to attend medical lectures.

Iona is Hazel’s loyal maid at Hawthornden Castle. She quietly supports Hazel's unconventional ambitions, helping her dress as a man to attend classes and assisting with her secret anatomical studies. She still mourns Hazel's older brother, George, whom she quietly loved.

Charles is a footman employed at Hawthornden Castle. He works alongside the other household staff and shares a quiet, developing affection with the maid, Iona.

Munro is an older, experienced resurrection man who taught Jack the illegal trade of body snatching. He knows the ins and outs of bypassing graveyard security and serves as a mentor figure to the younger grave robbers operating in Edinburgh.

Davey is a young boy working as a resurrection man alongside Munro. He feels anxious about his grim profession and fears the returning Roman fever before falling victim to a sudden abduction in the graveyard.

Jeanette is a young maid newly employed at the Almonts' fashionable home. She supplements her income by feeding Jack information about recent burials, helping him locate fresh bodies for his resurrection work.

Isabella is a beautiful dancer at the Le Grand Leon theater. She is the object of Jack's early romantic affections, though her own romantic interests lie with the theater's lead actor.

Mr. Arthur is the practical boss at Le Grand Leon theater, managing the crew and performers. He employs Jack as an all-purpose assistant and allows the young man to sleep in the rafters above the stage.

Thomas is the lead actor at Le Grand Leon theater. He is romantically involved with the dancer Isabella and projects a confident, reassuring presence backstage.

Burgess is a male student enrolled in Dr. Beecham’s rigorous anatomy class. He struggles under the intense pressure of the surgical demonstrations and frequently faces bullying from other classmates until Hazel steps in to defend him.

Thrupp is a hostile and aggressive student in Dr. Beecham’s anatomy lectures. He deeply resents Hazel's immediate success in the classroom and frequently attempts to bully the other students to assert dominance.

Lord Almont is Bernard’s father, a wealthy and influential nobleman in Edinburgh. He utilizes his vast resources to purchase medical comforts, demonstrating little regard for the impoverished people exploited to improve his standard of living.

Jones is an associate of Dr. Beecham, easily identified by his tall top hat. He handles the physical labor required during demonstrations and assists the surgeon in managing unruly patients.