Throughout the novel, Jonathan Safran Foer occasionally inserts photographs of doorknobs into the text. Grandpa
took meticulous photographs of everything in his apartment, including doorknobs, so the collection of doorknobs comes in part from Grandpa’s trove of photographs. During the firebombing of Dresden, Grandpa burned his hand on a metal doorknob, which was all that was left of his home. The recurring photographs of doorknobs burn this visual motif throughout the novel like a scar. Throughout the novel, characters frequently stand on thresholds, both literal and metaphorical. Oskar has to meet every person named Black on his list by approaching his or her front door. When Oskar’s grandfather moves back into the apartment, he is relegated to the guest room. The doorknob also shows a lock, reminding the reader visually throughout the novel that Oskar is searching for the right lock that matches his mysterious key.