In a vase in a closet a couple of years after his father died in 9/11 nine-year-old Oskar discovers a key . . .The key belonged to his father hes sure of that. But which of New Yorks 162 million locks does it open?So begins a quest that takes Oskar - inventor letter-writer and amateur detective - across New Yorks five boroughs and into the jumbled lives of friends relatives and complete strangers. He gets heavy boots he gives himself little bruises and he inches ever nearer to the heart of a family mystery that stretches back fifty years. But will it take him any closer to or even further from his lost father?