The Mother is an elderly Russian immigrant living in a two-room apartment in America. She wears inexpensive black clothing and approaches her family's ongoing hardships with stoic acceptance. Her days revolve around mundane tasks like preparing dinner, yet she carries profound grief from her family's displacement and her son's severe psychiatric condition. She possesses enough English proficiency to answer the telephone.

The Father is an elderly man who struggles with physical ailments and the indignity of relying on his brother for money after being a successful businessman in Europe. He reads a Russian-language newspaper and speaks poor English, isolating him from American society. He processes his sorrow through periods of brooding silence and sudden bursts of desperate optimism.

The Son is a young man confined to a psychiatric hospital due to a condition called referential mania. He believes everything in the natural and man-made world is secretly communicating about him. His severe mental health struggles stem partially from a chaotic upbringing as a refugee, leading him to frequent suicide attempts in an effort to escape his surroundings.

Isaac is the Father's brother who immigrated to the United States decades earlier. He is financially stable and considered a real American by his relatives. He provides the money that allows his brother and sister-in-law to survive. His financial success stands in sharp contrast to their poverty.

Aunt Rosa is a deceased relative from the family's time in Europe. She lived a fussy, anxious life before being killed during the Holocaust. Her memory serves as a direct link to the family's traumatic past and the broader historical tragedies they escaped.

The Nurse works at the psychiatric hospital where the Son is institutionalized. She maintains a strangely cheerful disposition while delivering distressing news about the patients. She acts as a gatekeeper between the parents and their child.

The Doctor is a medical professional at the sanitarium who assesses the Son's psychiatric condition. He views the Son's actions with clinical detachment. He documents his symptoms in scientific journals rather than showing emotional concern for the family.

The Unknown Caller is a young woman who repeatedly telephones the family's apartment after midnight. She speaks English and asks for someone who does not live there. Her calls create a frustrating language barrier and interrupt the parents' late-night conversation.

Charlie is an unidentified individual whom the late-night caller is trying to reach. He does not live at the parents' apartment. The search for him causes a persistent communication breakdown on the telephone.