'Five Portraits of the Insane' by the nineteenth century French artist Théodore Géricault are said to be all that remain of originally ten commissioned portraits of insane patients. Each painting depicts a particular mental condition, a so-called monomania including a kleptomaniac, a woman mad with envy, and a child kidnapper. Almost nothing is known about these portraits, but they raise a multitude of questions. Who are these people? In what way are they insane? What and where are the five missing madnesses? Intrigued and inspired by an absence, Tan decides to go in search of them. Pairing personal impressions with formal analysis and archival research, the essay ventures far beyond the boundaries of art history.