Heather is a first-year medical student who quickly finds herself overwhelmed by the intense academic workload at DeWitt. She enters the school with idealistic expectations and relies on her long-distance boyfriend for emotional support. Her confidence plummets after failing her initial anatomy quizzes. She is earnest and strives to connect with her lab partners despite the competitive atmosphere.

Rachel is Heather’s deeply cynical roommate. She views medical school as a cutthroat game and hides her loneliness behind a hardened exterior. Struggling with the coursework, she relies on her past strategy of seducing professors to secure better grades, specifically targeting the anatomy instructor.

Abe is an imposing but gentle first-year student and Mason's roommate. Coming from a working-class background, he struggles to afford his tuition, prompting him to take a high-paying job at a rundown off-campus clinic. He is fiercely loyal and deeply protective of his friends, prioritizing their well-being over his own.

Mason is a highly ambitious and arrogant medical student determined to secure a prestigious plastic surgery residency. He aims to outshine the legacy of his famous surgeon father. As the top student in the class, he treats most of his peers with a mix of charm and condescension, viewing medical school as a competition he is destined to win.

Sasha is an older, intensely driven medical student from a working-class Russian immigrant family. She is determined to graduate at the top of her class to honor her late father, who died from Parkinson's disease. Her grief and financial struggles fuel a simmering resentment toward her wealthier classmates, particularly those she feels have unearned advantages.

Dr. Conlon is DeWitt's dedicated anatomy professor. He is a former medical student who transitioned to teaching after a traumatic event left him with a permanent limp and physical disabilities. He is highly invested in his students' academic success, offering extra tutoring to those who struggle, but he lives an isolated personal life.

Dr. Winters is the wellness counselor at DeWitt Medical School. She presents herself as a supportive resource offering a safe space for students struggling with academic pressure. However, her professional facade masks ulterior motives regarding the student body and faculty.

Dr. Kovak is a physician who runs a shady off-campus clinic. He offers excellent pay to medical students willing to work the front desk, utilizing financial incentives to ensure their compliance with his questionable business practices.

Frank is the cadaver assigned to Heather, Rachel, Abe, Mason, and Sasha. His faded arm tattoo indicates he was once a police officer, and his unusually healthy organs prompt intense curiosity from the students dissecting him.

Danielle is a diligent first-year medical student hoping to match into dermatology. She frequently works late into the night dissecting her assigned cadaver, Agatha.

Victor is a highly anxious medical student at DeWitt who struggles academically. He attends remedial tutoring and frequently seeks out questionable methods to cope with his stress and poor grades.

Landon is Heather's long-distance boyfriend at the beginning of her first year. He serves as her primary emotional stability, though the distance quickly strains their connection.

Dr. Howard is Mason's father and the head of cardiothoracic surgery at Yale. He is a wealthy, imposing, and highly successful physician whose legacy casts a massive shadow over his son's ambitions.

Mason's protective and wealthy mother. She maintains extremely high expectations for her son's future and is visibly critical of anyone she feels does not fit into their affluent lifestyle.

A Russian immigrant who moved to America to provide for his children. His death from Parkinson's disease serves as the foundational trauma and driving motivation for Sasha's intense academic ambition.

Sasha's mother, who speaks primarily Russian and still lives in Brooklyn. She struggles with loneliness following her husband's death and wishes her daughter would prioritize family over a grueling medical education.

Dr. Conlon's secretary at the medical school. She manages his schedule, protects his privacy, and acts as a strict gatekeeper for his office.