This article considers a demonological tractate authored in the 1230s by Roland of Cremona, a learned physician who became the first Dominican master of theology in Paris. The core of the article is an analysis of the interaction of the popular and the learned through his original, hitherto overlooked account of a popular practice he names cursus, a nightly orgiastic flight induced by smearing a certain ointment. Antedating by two hundred years the first known sources to mention flying ointments, and independent of earlier sources about the nightly ladies, I delineate its importance to the study of the medieval origins of the witches' sabbat.