Mado is a 21-year-old woman with short hair who wears tailored jackets and ties. Raised by a widowed Parisian greengrocer whose paralysis shaped her early life, she harbors intense anger over social inequality. She boards the train carrying a homemade bomb concealed in her lunch bucket, intending to strike at the political elite traveling to the National Assembly.

Blonska is a 60-year-old Russian émigrée traveling in Third Class. She lives in extreme poverty, choosing to sleep on platforms to save her money for charitable causes in Paris. Despite her own hardships, she pays close attention to the suffering of those around her and believes in practical, incremental care over violent revolution.

Guillaume is the 35-year-old driver of Engine 721. As a third-generation railway worker, he is highly skilled but operates under immense pressure from the company's dual demands for fuel efficiency and strict punctuality. He focuses heavily on securing his Christmas bonus to support his family, making calculated decisions regarding the train's speed.

Victor is the stoker for Engine 721, responsible for constantly feeding coal to maintain steam pressure. He shares cramped working quarters and lodgings with Guillaume, creating an intensely close bond. He constantly calculates the physical and financial costs of the journey, weighing coal expenditure against the promise of a holiday bonus.

Henry is a Black American painter living in Paris. He travels in Second Class rather than First to avoid the exhausting racial vigilance and prejudice he frequently encounters among the elite. He carries deep psychological scars from racial abuse in his past, which manifest in extreme physical anxiety when his right to occupy a space is questioned.

Marcelle is a 22-year-old physiology student typing her supervisor's research notes on a portable Dactyle typewriter. As the daughter of a Cuban-born former politician, she faces dismissive attitudes regarding both her race and her gender. She approaches the world with clinical curiosity, frequently observing the physical symptoms and behaviors of those around her.

Maurice is a seven-year-old boy traveling alone for the first time from Granville to Dreux. Armed with a copy of Around the World in Eighty Days, he approaches the journey with a mix of wonder and sharp curiosity. His innocent questions frequently expose the illogical rules and artificial systems governing adult life on the railway.

Léon is the 42-year-old senior guard of the express, responsible for documentation, baggage, and maintaining strict company standards. A former Zouave soldier, he suffers from chronic back pain exacerbated by his stiff uniform and the physical demands of his job. He relies heavily on mottos to enforce his strict adherence to rules.

Cécile is a young, unmarried blonde woman traveling to Paris. She is heavily pregnant with the child of a soldier stationed in Madagascar. She struggles with physical discomfort during the journey and plans to quietly pass her child off to her sister to avoid social ruin.

Alice is the 22-year-old secretary to a camera-firm owner. Fascinated by the new technology of moving pictures, she carries a Demenÿ chronophotographic camera. She is highly aware of social propriety, carefully managing her seating arrangements to protect her reputation while trying to pitch creative filmmaking ideas to her dismissive employer.

Léon is a married camera-firm owner returning from a trip to a lens supplier. He is heavily focused on the business aspects of photography and remains skeptical of his secretary's proposals to produce narrative moving pictures. He also misinterprets professional enthusiasm as romantic interest.

Jean is the junior guard on the express. He handles luggage, manages the boarding of passengers, and acts as a messenger between the station platforms and the engine crew. The strict railway timetable forces him to prioritize speed over gentleness when dealing with lower-class passengers.

Louise is the wife of a wealthy automobile maker, traveling with her sickly teenage daughter. She is fiercely protective of her child and highly sensitive to social boundaries, reacting with intense hostility when a student offers unsolicited medical observations about her daughter's condition.

Émile is a successful automobile maker who enjoys the luxuries of First Class. He appreciates speed and modern engineering, viewing the rapid pace of the express train as a thrilling luxury rather than a mechanical risk.

Jeanne is the 17-year-old daughter of an automobile maker. She exhibits troubling physical symptoms, including extreme pallor and unusual bruising, which worry her mother and draw the medical attention of a fellow passenger.

Albert is the parliamentary deputy for Orne and a bank governor. He uses his considerable wealth and influence to attach his private carriage to the moving express, indifferent to the delays this causes the crew. Behind his respectable public image, he covertly seeks out sexual encounters with men at station stops.

Anna is the invalid wife of a parliamentary deputy. She travels with a greyhound and her grandson, requiring frequent assistance and water while remaining largely unaware of her husband's secret activities during their journey.

Jules-Félix is a 70-year-old munitions factory owner and parliamentary deputy. He is a staunch defender of his own factory's labor practices and views himself as an important political figure. His presence on the train attracts the dangerous attention of an anarchist passenger.

Emma is the wife of a munitions manufacturer. She travels comfortably, sharing luxury hampers of food with her companions and engaging in lighthearted teasing when another politician is forced to join their carriage to hide an indiscretion.

Fulgence is an engineer in chief for bridges and roads who lost an arm in his line of work. He spends his journey working on ambitious proposals for an underground electric railway network for Paris, dreaming of uniform, affordable transit.

Marie is an impoverished newspaper seller who stands near the tram terminus below the elevated railway station. Earning a meager living selling papers for pennies, she represents the working-class citizens who exist entirely outside the privileged world of the express train.

Hakim is a North African coffee seller traveling in Third Class. Strapped to a heavy dispensing tank, he struggles to find comfort in the crowded carriage and shares stories of being exoticized and displayed for money at the Parisian Exposition.

The comte is a parliamentary deputy for Orne who attempts to hide the fact that he is traveling with a married woman who is not his wife. Forced to separate from her to maintain appearances, he bluffs his way through an awkward journey in a carriage with his political colleagues.

John is a 24-year-old Irish writer observing his fellow passengers. He uses the train journey to collect material, engaging the diverse group of travelers in his carriage with traditional folktales and music.

Annah is a young woman traveling in Third Class with a monkey on her shoulder. She works at a death-themed cabaret and eagerly participates in the communal storytelling and music within her carriage.

Max is a Breton Jewish student attending the Colonial School. He shares space with a diverse group of passengers and opens up about his painful past, including the severe antisemitic bullying he faced in his youth.

Kiouaup is a Cambodian student at the Colonial School in Paris. He travels alongside his roommate, experiencing the crowded and diverse atmosphere of the lower-class carriage.

Madame Baudin is a Breton maid returning to Paris after visiting her daughter. She forms part of the temporary community in the Third-Class carriage, sharing stories and provisions with the strangers around her.