Extremely Loud and Incredibly Close

A nine-year-old boy on a quest to find the lock that fits a mysterious key left by his father, who died on 9/11.

Oskar's father, whose death in the World Trade Center attacks sets the novel's search in motion.

Oskar's grandmother, who lives in the same building and provides a source of comfort and stability for him.

Oskar's grandfather, a mute figure known as the renter, whose story unfolds through letters and whom Oskar meets late in the book.

Oskar's mother, who is grieving herself and begins seeing a man named Ron, whom Oskar resents.