For three months, Sergeant Major von Rumpel has traveled through Berlin and other cities, depositing gems and jewels from other nations. He stays in luxurious hotels whenever he travels on behalf of the Reich. His only failure so far is his failure to find the legendary Sea of Flames diamond. The stone he found in the Natural History Museum was a fake—just a piece of glass. Nevertheless, von Rumpel manages to track down the talented jeweler who designed the fake stone: a half-Algerian man named Dupont. Von Rumpel arranges for Dupont to be arrested, and then brings Dupont to speak with him. Von Rumpel, speaking French, begins his interrogation of the man, hoping for names he can use to find the diamond.
The “diamond plot” of the novel is more conventionally enjoyable than the other two plots (Werner’s life and Marie-Laure’s life). Indeed, in his review of the book, writer William Vollmann compared the diamond plot to stories in the Indiana Jones films. Von Rumpel is a villainous detective, using intimidation and bribery to hunt down a valuable object. Perhaps it’s necessary for Doerr’s novel to have a subplot of this kind, however—the thrills and mysteries of these chapters help to balance out the heady themes that Werner and Marie-Laure confront, and keep the story moving at a fast pace.