Leo Gursky is introduced as an elderly retired locksmith in Manhattan who fears dying alone and unseen.

Charlotte Singer receives a letter from a man named Jacob Marcus offering $100,000 to translate The History of Love.

Alma Singer secretly replaces her mother's letter with a forged romantic note addressed to Jacob Marcus.

A copy of The History of Love ends up in a Buenos Aires bookshop, where a traveling David Singer discovers and buys it.

Leo mails his life story manuscript, Words for Everything, to his son, the famous writer Isaac Moritz.

Leo reads Isaac Moritz's obituary on the back of a newspaper in a coffee shop.

Leo returns home from Isaac's funeral to find a brown paper package containing The History of Love manuscript.

Alma Singer notices that the name Alma Mereminski is Polish while every other name in the book is Spanish.

Alma Singer finds a marriage record for Alma Mereminski, then a doorman confirms Alma Moritz has died.

Litvinoff transcribes The History of Love with Spanish names and a South American setting, publishing it under his own name.

Rosa reads Leo's letter requesting his manuscript back, tears it up, and floods the house to destroy the original.

Alma reads the opening of Isaac Moritz's famous novel and discovers the protagonist is named Jacob Marcus.

Leo's own words from Words for Everything appear in a literary magazine credited to Isaac Moritz.

Bird writes a forged letter to Leo signed by Alma, asking him to meet in Central Park on Saturday.

Leo and Alma Singer meet on a park bench in Central Park and gradually understand how they are connected.

Leo Gursky is an elderly, isolated man in Manhattan who has spent his life unseen and cut off from everyone he loved. After mailing his memoir to his son Isaac, Leo is devastated to read the writer's obituary in a coffee shop and attends the funeral as a stranger. Back home, he discovers a mysterious package containing his own long-lost manuscript, The History of Love, which he wrote as a young man in Poland. Meanwhile, in Brooklyn, teenage Alma Singer intercepts her mother's correspondence about translating the same book and begins a city-wide search for the man who commissioned it. The two investigations converge as Alma traces the book's characters to real people, and Bird delivers a forged letter that brings Leo and Alma to the same park bench. Their meeting in Central Park closes the circle, connecting the elderly writer to the girl named after the woman he loved.

The headline events connecting Leo, Alma Singer, and The History of Love.

Leo calls a number in the newspaper to pose as a nude model, desperate to be seen by as many people as possible.

David Singer gives Charlotte the copy of The History of Love at the beginning of their courtship.

Leo arrives late to Isaac's funeral and is mistaken by Isaac's half-brother Bernard for a long-lost relative from Slonim.

Leo discovers a faded photograph of himself as a boy with Alma Mereminski among Isaac's belongings and steals it.

Leo goes to the library and asks for every book written by Leo Gursky, finding only an unrelated children's book.

Alma's uncle Julian arrives from London, and over dinner Alma admits to him that she read his private letter.

Alma and Misha share an awkward first kiss, and Alma immediately tells him she likes someone else.

Alma visits the NYC Municipal Archives to search for Alma Mereminski's birth or death records but finds nothing.

Litvinoff says a final goodbye to his friend in Poland and receives a sealed package to hold for Leopold Gursky.

Bruno tricks Leo into boarding the Connecticut train alone at the last second, closing the doors between them.

Leo breaks into Isaac's house, puts on his dead son's coat, and searches for any sign that Words for Everything was read.

Charlotte sends the next installment of her translation to Jacob Marcus before Alma can slip in a forged love letter.

Alma and a schoolmate drive to Isaac Moritz's Connecticut house, find no one home, and leave a note on the door.

Bird goes to the airport with his lemonade savings to buy a ticket to Israel and tells the attendant he might be the Messiah.

Leo receives a letter signed by Alma asking for a meeting and becomes convinced she is an angel arriving to escort him to death.

Beneath the main plot, a series of quieter but pivotal moments define each character and drive the story forward. Leo draws attention to himself by posing as a nude art model, desperate to be seen by as many people as possible, while Litvinoff's last farewell to Leo in Poland sets the tragic chain of plagiarism in motion. Alma's friendship with Misha fractures after an awkward kiss, and her uncle Julian's visit gives her a rare moment of adult honesty about love and loss. Leo's grief sends him all the way to his late son's house in Connecticut, where he is surrounded by Isaac's belongings but finds no proof his manuscript was ever read. Bird's failed attempt to fly to Israel and Alma's fruitless trip to Connecticut with a schoolmate capture how far each character is willing to go in pursuit of connection, before chance finally brings them all together.

The smaller but essential moments that shaped each character's journey.

Leo falls in love with his neighbor Alma Mereminski as a boy and begins writing The History of Love for her.

Leo suffers a heart attack that shatters his isolation and drives him to a typewriter for the first time in 57 years.

David Singer is diagnosed with cancer and dies nine months later, leaving Charlotte and the children in lasting grief.

Alma Singer assembles a list of nine clues about Jacob Marcus's true identity, hidden inside her wilderness survival notebook.

Litvinoff finds his friend Leo feverish and ill in a Warsaw apartment and stays through the night to care for him.

Litvinoff reads papers on Leo's desk and discovers a self-written obituary titled 'The Death of Leopold Gursky,' which he secretly pockets.

Leo lets himself into Carnegie Hall alone and has a vision of Alma Mereminski playing violin on the empty stage.

Leo realizes mid-conversation that Bruno is speaking Yiddish instead of the English they have always used together.

Alma realizes Alma Mereminski must have changed her name through marriage, explaining why no records exist under that name.

Litvinoff meets Rosa in Valparaíso and fears that if she gets too close she will discover he is a broken shell of a man.

Litvinoff opens Leo's sealed package for the first time and takes out The History of Love manuscript from inside.

Charlotte sees Isaac Moritz's obituary in the newspaper, and Alma tries but fails to tell her mother everything she has discovered.

Bird steals Alma's notebook and, misreading her clues, concludes she must be searching for her biological father.

Bernard Moritz reveals to Bird that Isaac believed Leopold Gursky was his birth father, based on letters found among his mother's things.

Leo confesses to Alma Singer that Bruno died in 1941 and that he invented him as an imaginary companion to survive his loneliness.

The novel's deepest turning points begin with young Leo falling in love with Alma Mereminski and writing a book that will outlive everyone he knows, and a heart attack decades later forces him back to his typewriter for the first time in years. Litvinoff's fateful night at Leo's sickbed in Poland gives him access to words that are not his own, and when he later opens Leo's sealed package, he uses the manuscript to build an entirely new identity with Rosa. In Brooklyn, Alma carefully assembles her clues about Jacob Marcus and makes the breakthrough realization that Alma Mereminski must have married and changed her name. Charlotte sees Isaac Moritz's obituary, and Alma finally understands that the man who commissioned the translation was Isaac himself, using his own fictional character's name as an alias. Bird's misreading of Alma's notebook and his interception of Bernard Moritz's call accidentally unlock the final secret, and the novel closes with Leo's quiet confession that his only companion Bruno has been an imaginary friend all along.