Extremely Loud and incredibly close

The main protagonist of Extremely Loud and Incredibly Close is a nine-year-old boy named Oskar Schell. Oskar Schell's father Thomas Schell dies in the teorist attack on the World Trade Center on September 11, 2001, before the narrative begins. While looking through his father's closet, Oskar finds a key in a small envelope inside a vase, on the outside of the envelope the word "Black" is written in the top left corner. Curious, Oskar sets off on a mission to contact every person in New York City with the last name Black, in alphabetical order, in order to find the lock to the key his father left behind. The novel also tells a separate narrative that eventually converges with the main story through a series of letters written by Oskar's grandfather to Oskar's father and by Oskar's grandmother to Oskar himself. Based on real life events.
One of the first people Oskar meets in his search for the key's origin is a forty-eight-year-old woman named Abby Black. Oskar makes friends instantly, but she has no information on the key. Oskar continues to search the city, meeting an old man he calls "the renter" – as he is the new tenant in Oskar's grandmother's apartment; "the renter" is actually Oskar's grandfather. Eight months after he meets Abby he finds a message on the answering machine. He had not touched that phone since his father died since his father's last words had been on an identical answering machine which Oskar had kept hidden from his mother. It is revealed that Abby had called Oskar directly after his visit, saying "she wasn't completely honest with Oskar, and she thinks that she might be able to help". Oskar returns to Abby's apartment, and Abby directs him to her ex-husband, William Black.