A 22-year-old medical student from an aristocratic Polish family in Vienna. Socially awkward and initially driven by a detached, intellectual fascination with medicine, he enlists in the Austro-Hungarian army seeking surgical experience. He finds himself entirely unprepared for the brutal, makeshift reality of wartime medicine at the Lemnowice field hospital.

A pragmatic, resourceful nursing sister managing the Lemnowice field hospital mostly alone. Adapted to the unforgiving environment of the Eastern Front, she handles everything from amputations to fending off threats with a weapon. She becomes a vital mentor to Lucius, teaching him the practical realities of frontline medicine and the importance of compassionate care.

A Hungarian soldier and artist from Budapest suffering from a profound case of war neurosis. Found catatonic in an abandoned ambulance, he communicates his trauma only through intricate, surreal sketches hidden in his coat. His case challenges the medical understanding of both Lucius and the military establishment.

A brutal and uncompromising conscription officer for the Austro-Hungarian army. He views soldiers suffering from psychological trauma as malingerers and cowards, embodying the military establishment's callous disregard for invisible wounds. His strict enforcement of battle readiness creates intense friction with the hospital staff.

Lucius's mother, a pragmatic and formidable woman who transformed the Krzelewski family's mining interests into a massive fortune by supplying the military. She values social standing and attempts to manipulate Lucius's military career to benefit the family's patriotic image.

Lucius's father, a retired major and Polish aristocrat who lives deeply in the past. He embraces romanticized ideals of martial glory and the cavalry, eagerly dressing his son in antique armor and encouraging his enlistment with tales of historical battles.

An eccentric, elderly anatomy professor at the university in Vienna. Though brilliant in diagnosis, his research reflects the esoteric and detached nature of academic medicine that Lucius experiences before leaving for the war.

A fellow medical student and one of Lucius's few friends, the son of a tailor. He is an outsider in the Austrian student associations and eagerly enlists when the war begins, viewing it as a thrilling opportunity for surgical experience.

A scholarship medical student in Vienna who befriends Lucius. Like Feuermann, he is an outsider who eagerly joins the military at the outbreak of the war.

An orderly at the Lemnowice hospital and a former postman from outside Kraków. He is a passionate philatelist who collects stamps, even risking his life during a Christmas truce to trade with a Russian soldier.

A young Ruthenian cook and orderly at the hospital who lost his hand at the battle of Lemberg. Despite his amputation, he manages the hospital's meager food supplies and remains a steady presence among the staff.

A very large former oil field worker from Drohobycz serving as an orderly. He takes great pride in sharing a name with a character from a famous Polish novel and claims to possess immense mental strength.

An orderly at the Lemnowice field hospital. He is named "Second Nowak" because his predecessor died of dysentery shortly after Lucius's arrival.

Lucius's predecessor at the Lemnowice hospital. A Hungarian doctor who became so overwhelmed by a severe lice infestation and psychological terror that he fled his post months before Lucius's arrival.

The poised and beautiful daughter of a Polish general. She engages Lucius intellectually when they are introduced in Vienna's high society, handling the social collapse of the old aristocracy with sophistication and pragmatism.

A young Polish woman traveling with her feverish son, Paweł, in search of her missing husband. She demonstrates quick thinking and resourcefulness when surviving dangerous military checkpoints.

A renowned scientist and Nobel Prize winner who catches Lucius and Zimmer sneaking out of the museum with a dried mermaid corpse. She questions Lucius about his work and advises him to seek better mentors.

The father of Lucius's friend Feuermann. He shares news regarding his son's military deployment when Lucius seeks him out in Vienna.

Lucius's cousin who tearfully enlists when war is declared, claiming the conflict makes him feel Austrian for the first time.

A renowned anatomist in Vienna who recognizes Lucius's unusual aptitude for identifying bones strictly by touch.

Adelajda's feverish young son. During a train journey, Lucius examines him and advises against the patent medicines being used to treat his illness.