The Duplicate takes place in an unnamed town near a beach, where the protagonist, sixteen-year-old David, has always enjoyed walking when he needs to think. Such is the case at the beginning of the novel—David is walking the dunes, his head filled with romantic thoughts of Angela. As he walks, David notices that a recent storm has washed up from the ocean "satisfyingly disgusting things," such as seaweed, jellyfish, seagulls with broken necks, and dead fish. He also finds that the storm has washed up a box that looks like a cross between a postal meter scale and a video camera—the Spee-Dee-Dupe.

Much of the first part of the novel is set at David's home and at his school, both of which are described only briefly. The second half of the novel takes place in a much more exotic location, a deserted World War...