Paul is a young, articulate Black man who introduces himself to wealthy New Yorkers as a Harvard classmate of their children and the son of famous actor Sidney Poitier. He possesses an extensive knowledge of art, literature, and high-society manners, which he uses to charm his affluent hosts. He speaks eloquently about theories of imagination and demonstrates unexpected domestic skills by cooking elaborate meals from leftovers.

Ouisa is a wealthy, middle-aged New York socialite who lives in a luxurious apartment featuring a double-sided Kandinsky painting. She views herself as socially progressive, though her worldview is heavily insulated by extreme wealth and privilege. She finds herself unexpectedly enchanted by Paul's intellect, eventually viewing him as a more appealing presence than her own children.

Flan is Ouisa's husband and a high-end art dealer. While he once possessed a genuine passion for the aesthetics of art, he now operates in a world where paintings are primarily vehicles for multi-million-dollar transactions. He is highly focused on securing a two-million-dollar loan to flip a Cezanne painting for a massive profit.

A young student at MIT who comes from a highly privileged background. He keeps a detailed address book of his wealthy boarding school peers and their families. He shares his extensive knowledge of upper-class dialect, pronunciation, and social habits with Paul during a period they spend together in Boston.

An exceptionally wealthy South African businessman with massive investments in gold mines. He is visiting New York and represents a crucial financial opportunity for Flan's art dealing business. He adopts a paternalistic view toward the racial politics of his home country.

A wealthy peer of Ouisa and Flan whose children attend the same elite boarding schools. She moves in the same exclusive New York social circles and finds her household similarly disrupted by a bizarre nighttime encounter.

Kitty's husband and a member of the same elite New York social circle as Flan. He shares in the collective panic regarding unexpected events and prefers not to inquire too deeply into his wife's private connections.

An earnest physician who deeply admires the civil rights achievements of Sidney Poitier. He provides immediate medical attention and trust to a young man claiming to know his son, attempting to prove he is a supportive and liberal figure.

Ouisa and Flan's rebellious daughter. She is highly critical of her parents' superficial values and threatens extreme lifestyle changes specifically to agitate them. She actively investigates the origins of the stranger who entered their home.

Dr. Fine's openly hostile son. He harbors deep resentment toward his father and completely rejects his attempts to reach out or perform favors.

A young, naive aspiring actor from Utah trying to build a life in New York City. He is generous and welcoming, willing to share his small "railroad loft" with a new acquaintance who claims to be sleeping in the park.

Rick's roommate and fellow aspiring actor from Utah. She takes acting technique seriously and is slightly more protective of their shared resources than Rick when faced with a charming stranger.

Ouisa and Flan's son, who attends an elite boarding school. He shares his sister's intense embarrassment regarding their parents' dramatic reactions to social disruptions.

Another of Ouisa and Flan's sons. His identity as a student at an elite institution serves as a functional reference point in upper-class social circles.

Kitty and Larkin's son. He joins the other teenagers in groaning at the frantic, overlapping complaints of the adults in their social circle.

A pragmatic, weary New York police officer called in to investigate the bizarre home intrusions experienced by the Kittredges and their friends. He is frustrated by their inability to articulate an actual crime.

An employee at Ouisa and Flan's luxurious building. He manages access to their exclusive living space and occasionally interacts with the fallout of their social lives.

An unexpected, aggressive guest brought into the Kittredge apartment late at night. His sudden presence shatters the polite illusion maintained in the household.