Ari is a 48-year-old former prisoner who travels through a fractured, post-collapse United States. She relies heavily on lifelong premonitions to survive treacherous situations, including a career conducting surveillance for a local militia. Across her life, she works in arms dealing and eventually establishes herself as a wealthy art collector in Paris.

Ibari is a 79-year-old high-ranking detective in the authoritarian State's Internal Security Service. She maintains a long-standing cover as an urban planning professor, living a disciplined and highly regulated life. Her accidental discovery that silver tape on her glasses foils facial recognition technology sparks her disillusionment with the government she serves.

Gloria is a refugee who fled militia violence in Tennessee to live in the Republic of California. She carries deep psychological trauma and a distinctive forehead scar from surviving a suicide bombing. She later moves to Europe, where her unresolved fears make her an emotionally distant parent.

Nico is a brilliant physicist working on teleportation experiments within the technologically advanced State. When an experiment malfunctions, she finds herself transported to a parallel universe, permanently separating her from her husband and children. She focuses her energy on seeking a way back while stepping into a maternal role for others.

Kareem is a friendly man who throws a party in Los Angeles to celebrate the secession of the California Republic. During the event, he notices strange "extra people" before abruptly disappearing from his own kitchen, leaving behind his life and his friend Gloria.

Fayed is a quantum physicist living in the surveillance-heavy State, deeply involved in subversive teleportation experiments alongside his wife, Nico. He is highly ambitious and prioritizes his scientific work and ideological goals over his familial responsibilities.

Sebastian is the son of Gloria, raised in France with minimal affection from his mother. He develops a lifelong obsession with reclaiming a painting titled Swan Dive, which once belonged to his father. His meticulous efforts to acquire the artwork push him toward dangerous choices.

Marlowe is a 34-year-old academic residing in the State. She struggles with isolation and the lingering psychological effects of an emotionally abusive marriage, which has eroded her trust in her own perceptions.

Samir is an architect working on Colony One. Living under the State's constant surveillance, he faces the heavy burden of being forced to act as an informant, reporting on his own family members.

Felix is a former professional ballet dancer who works as an arms dealer in the fractured United States. He partners with Ari as they flee escalating militia warfare, though his carelessness frequently puts them in jeopardy.

James is Kareem's roommate. After witnessing the impossible events at their gathering, he becomes consumed by the mystery, theorizing that the apartment acted as a "door" between realities.

Bill is a wealthy individual who specializes in transporting people to new identities. He recognizes Ari's resourcefulness during a crisis and brings her into his affluent life in Paris.

Eddie is a talented pianist and Ari's late wife. Her memory remains a powerful, grounding presence in Ari's life during her later years as an art collector.

Anton is the cousin of Ari and Ibari. His involvement in illegal smuggling operations leads to a severe conflict with Ari, profoundly altering both of their lives.

Hugo is Marlowe's husband, whose persistent emotional abuse and manipulation severely damage her sense of reality and self-worth.

Saraya is a colleague of Nico's who participates in a dangerous teleportation experiment. A displaced version of her appears unexpectedly at Kareem's gathering.

Eduardo is a member of the Cincinnati United Militia who employs Ari to conduct surveillance assignments in the unstable Ohio Republic.

Lucas is a painter who creates Swan Dive, a piece of art depicting a diver disappearing into water. His artwork becomes deeply significant to multiple characters across different timelines.

Haruki is Ibari's boss at the Internal Security Service. He oversees her work enforcing the State's strict surveillance mandates.

Alberto is a superior at the Internal Security Service who informs Ibari of critical developments regarding subversive scientific experiments.

Obie is a criminal acquaintance of Sebastian who assists him in managing the fallout from a disastrous theft, drawing Sebastian into the underworld.

Olivia is an artist who shares a competitive relationship with Lucas Alkaitis and sits for a portrait in his New York studio.

David is a corrupt colleague of Ibari's within the Internal Security Service. He provides her with cover after she uses recorded evidence to blackmail him.

Latika is a hairstylist and informant who provides Ibari with the critical accusation needed to gain leverage over David Grissom.

Ilieva is a friend of Ari's who gets drawn into a dangerous human trafficking operation by a Russian criminal.

Pilar is Ari's assistant in Paris, providing logistical support to the wealthy art collector.