Theories of Forgetting is a narrative in three parts. The first is the story of Alana, a filmmaker struggling to complete a short documentary about Robert Smithson's famous earthwork, The Spiral Jetty, located where the Great Salt Lake meets the desert. Alana falls victim to a pandemic called The Frost, whose symptoms include an increasing sensation of coldness and growing amnesia. The second involves Alana's husband, Hugh, owner of a rare-and-used bookstore in Salt Lake City, and his slow disappearance across Jordan while on a trip both to remember and to forget Alana's death. The third involves marginalia added to Hugh's section by his daughter, Aila, an art critic living in Berlin. Aila discovers a manuscript by her father after his disappearance and tries to make sense of it by means of a one-sided "dialogue" with her brother, Lance.

Each page of the novel is divided in half. Alana's narrative runs across the top of the page, from back to front, while Hugh's and his daughter's tale runs "upside down" across the bottom of the page, from front to back. How a reader initially happens to pick up Theories of Forgetting determines which narrative is read first, and thereby establishing the reader's meaning-making of the novel.