This chapter offers a case study of El hombre descuadernado (2009), a comic book adaptation of Guy de Maupassant’s « The Horla » (1886) by Spanish writer Felipe Hernández Cava and Argentinian artist Sanyú. If one considers a good adaptation to be a free adaptation, i.e. one which betrays its source rather than reproduce it, then literary classics provide many opportunities for adaptations insomuch as they are open to multiple readings and to the specific concerns of various eras (in this case, a parallel is made between the figure of the Horla and Alzheimer’s disease). Thus, after exploring Cava’s reasons for adapting the novella with its motifs of disease, madness, fear and the double, this chapter analyzes some of the visual and narrative strategies which, it would seem, aim at embodying madness and involving the reader in it by subverting graphic storytelling codes.