When his wife Hélène dies at just thirty-three years old, Julien Azoulay, a writer of romantic comedies, is devastated. However, Hélène made her husband promise her one thing: after her death, Julien should write her thirty-three letters—one for each year of her life. To his surprise, Julien finds that writing the letters strangely comforts him. He tells Hélène about the life he must now lead without her. About his love, which no longer receives any answers. About their son Arthur, who doesn’t want a sad dad. About Cathérine, who wishes to comfort him but is herself too unhappy over the loss of her friend. Hélène is buried in the cemetery at Montmartre, and there, in a secret compartment at the gravestone, Julien places his correspondence. But one day, all the letters are gone. Instead of them, Julien discovers a small heart made of stone. Julie.