This essay focuses on the recurrent metaphor of a painstaking journey in Bruno Latour’s An Inquiry into Modes of Existence and the ways in which it can be deployed as a reading of the world. I use this metaphor to scrutinize the transmission, in manuscript Chantilly, Musée Condé 653, of Antoine de la Sale’s Le Paradis de la Reine Sibylle, a fifteenth-century account of travel to, and myths associated with, the Monte della Sibilla in the Apennine Mountains of Italy. From a Latourian perspective, Chantilly 653 attests to the agency of a mountainous landscape and the myths that inhabit it, as well as to the ways in which myths solicit representation in material form. In this instance, material form is a medieval manuscript, one that can be read, through a Latourian lens, as a set of category crossings that bring together points in space and time. Those points are not organized as historical periods but rather as modes of understanding the world.