Leopold, who goes by Leo, is an elderly, retired locksmith living alone in a crowded apartment with a weak heart. Originally from Poland, he survived World War II by hiding in forests and eventually immigrated to the United States. In his youth, he was an aspiring writer who penned a manuscript titled *The History of Love* for the girl he loved. He lives with a pervasive fear of disappearing or going unseen, prompting him to cause small public scenes so others acknowledge his existence.

Alma is a highly observant teenager living in Brooklyn who acts as a protective force for her grieving family. Named after the heroine in a mysterious Spanish book called *The History of Love*, she copes with her father's death by studying wilderness survival and keeping detailed instructional notebooks. She feels a heavy responsibility to cure her mother's loneliness and carefully monitors her younger brother's strange behaviors.

Zvi is a Polish refugee who settles in Valparaíso, Chile, where he works teaching Hebrew and literature. He is credited as the author of the Spanish-language novel *The History of Love*, which sees a small publication run before slowly spreading across the world. He lives a quiet life with his wife while harboring deep insecurities about his literary abilities and carrying immense guilt over his wartime losses.

Emanuel is Alma's younger brother, nicknamed Bird after attempting to fly out of a second-story window at age six. At nine years old, he is devoutly religious and believes he might be a *lamed vovnik*, one of thirty-six holy people capable of speaking directly to God. He copes with the absence of his father by retreating into rigid spiritual rules, selling lemonade to fund his religious missions, and embarking on strange private construction projects.

Bruno is Leo Gursky's neighbor and childhood friend from Poland. Having reconnected with Leo on a New York sidewalk years after the war, he lives in the apartment directly above Leo's. The two elderly men serve as each other's primary companions and anchors to reality, communicating through the radiator and sharing meals to stave off loneliness.

Alma is Leo Gursky's childhood sweetheart from Poland and the original inspiration for his manuscript. She immigrates to the United States before the outbreak of World War II to escape the looming threat in Europe. Believing Leo perished in the conflict when he stops responding to her letters, she eventually builds a new life and a family in New York.

Charlotte is an English-born translator living in Brooklyn and the widowed mother of Alma and Bird. Since the death of her husband, David, she has grown increasingly withdrawn, subsisting mostly on literature and her translation work. She isolates herself behind stacks of dictionaries and rarely leaves the house, prompting her daughter's constant worry about her happiness.

David is Charlotte's late husband and the father of Alma and Bird. Before his passing from cancer, he purchased a copy of *The History of Love* while traveling in South America and gifted it to Charlotte when they met in Israel. Though he is dead before the novel begins, his memory profoundly shapes the lives and coping mechanisms of his surviving family members.

Misha is a Russian immigrant teenager living in New York who becomes Alma Singer's close friend. The two begin communicating as pen pals before meeting in person at his Bar Mitzvah. He serves as Alma's primary confidant regarding her efforts to investigate mysterious letters sent to her mother, though their dynamic grows complicated as they experience adolescence.

Isaac is a highly successful and critically acclaimed author living in Connecticut. He is the son of Alma Mereminski, raised believing his mother's husband was his biological father. He leaves behind a complex literary legacy that prompts various characters to investigate his background and his written work.

Rosa is Zvi Litvinoff's wife, having met him in Valparaíso, Chile, in 1951. She assists him in translating a Yiddish manuscript into Spanish for publication. Devoted to her husband, she views it as her duty to shepherd his literary work into the world and fiercely protects his legacy as a writer.

Bernard is the half-brother of the famous writer Isaac Moritz and the son of Alma Mereminski. He helps manage his family's affairs and interacts with those inquiring about his late mother's past and his brother's literary estate.

Julian is Charlotte Singer's brother who visits from London. He provides a brief, stabilizing presence in the Singer household and treats his niece to thoughtful gifts, though he brings his own marital troubles from home.

Mr. Goldstein is the elderly janitor at the Hebrew School who mumbles in three languages. He is Bird Singer's only real friend and confidant outside of his family, providing a sympathetic ear for the boy's eccentric religious ideas.

Mordecai is the son of Alma Mereminski's boss in New York. He marries Alma after she immigrates to the United States and builds a family with her in Manhattan.