Odile is a sixteen-year-old student living in a valley bordered by alternate timelines. Quiet and insecure, she is pressured by her mother into joining the highly competitive Conseil vetting program. When she inadvertently spots visitors from the future near her school, she realizes a terrible tragedy is about to strike someone close to her, forcing her to bear the heavy weight of forbidden knowledge.

Edme is a kind, artistically inclined classmate who quickly befriends Odile. He dreams of playing the violin in the valley's orchestra, directly opposing his parents' demands for him to become a butcher. His secret musical aspirations represent a desire for personal freedom in a highly structured society.

A widow working in the archives beneath the Hôtel de Ville, Odile’s Mother firmly believes in the authority of the Conseil. She actively pushes her daughter to secure a prestigious position within the governing body. Behind her strict expectations, she quietly copes with the loss of her husband by drinking wine in the evenings.

Raimond is an older officer in the gendarmerie who takes a distinct interest in Odile. Socially isolated and often mocked by his peers, he views strict adherence to the valley's laws as a path to personal validation. He seeks authority and status to compensate for his own insecurities.

Alain is Edme’s closest friend and a rebellious presence at the school. He acts impulsively and frequently challenges authority figures, harboring deep resentment toward the valley's strict regulations. His fierce loyalty to his friends often places him at odds with the restrictive expectations of their society.

Jo is a confident classmate chosen alongside Odile for the rigorous Conseil program. Coming from a wealthy family that owns a local winery, she initially takes Odile under her wing. She offers rides to the Grand École and invites Odile into her broader social circle.

Mme. Ivret is a conseillière who instructs the students in the government program. She evaluates the candidates based on their ability to prioritize strict security over sentimentality when reviewing time travel requests. She actively pressures Odile to maintain absolute secrecy regarding the future.

M. Pichegru is a local school teacher who assigns his students a complex essay regarding time travel. He grades strictly on merit and inadvertently sets Odile's career path in motion by submitting her work to the Conseil.

Jean-Savile is a commandant in the gendarmerie who oversees border security operations. He holds significant authority over troop promotions and assignments, strictly enforcing the Conseil's laws and evaluating the loyalty of his subordinates.

Quinton is an older man and former schoolteacher suffering from a terminal illness. He submits an emotional petition to travel to the eastern valley to see his granddaughter, knowing he will not live long enough to meet her naturally.

Lucie is a young woman who originally participated in the first week of the vetting program alongside Odile. Years later, she attempts to bypass the border guards to flee a severely abusive marriage, exposing the harshness of the valley's enforcement protocols.

Justine is a member of Jo's friend circle who spends time socializing at the lake and the makeshift fort in the woods. She briefly dates Alain and enjoys the newfound camaraderie among the schoolmates.

Mme. Pira is Edme’s strict mother. She strongly opposes her son's musical aspirations, pushing him to abandon his violin for a practical career as a butcher. She is fiercely protective of her family's future and highly restrictive regarding Edme's free time.

Gagne is a second-in-command guard stationed on the western border. He is abrasive and frequently harasses the female gendarmes, representing the toxic and intimidating environment within the valley's military ranks.