Over the following weeks, Marie-Laure’s father forces her to practice moving about the city with her cane. She studies the model of the city and then tries to walk around the actual city, but finds it almost impossible to do so. One day in March, Marie-Laure has a breakthrough—she finds she’s no longer scared of moving on her own. She guides her father through the streets, all the way back to their home. When she reaches home, her father laughs—a beautiful laugh that Marie-Laure will remember all her life.
It’s important to understand that Doerr characterizes the relationship between Marie-Laure and her father (still unnamed in the narrative) as being long-lasting—he notes that Marie-Laure will remember her father’s laugh for the rest of her life. There’s a sadness in this sentence as well, however, the suggestion being that Marie-Laure will lose her father and be left with only happy memories of him.