This article explores Catholic missionaries’ use of emotions to promote conversions in the duchy of Chablais from 1597 to 1598, highlighting in particular three Forty Hours Devotions celebrated in the Alpine villages of Annemasse and Thonon. Evoking early Christianity through images of the Eucharist and the Crucifixion, a small band of missionaries, led by François de Sales and Capuchin Chérubin de Maurienne, hoped to spark overt emotions in their audience and to distinguish baroque Catholicism from the more introspective Calvinist faith of nearby Geneva. Published accounts of the devotions, correspondence of the organizers, and records of the reactions from Geneva indicate the success of the Forty Hours Devotions and demonstrate the missionaries’ willingness to shape the presentation of their message to appeal to people’s senses rather than to their intellects.