“Mystery”: the word is often used to describe what remains secret to us. Among theologians, it designates a truth inaccessible to reason, but which the divine offers to be known by revealing itself. The painter François-Xavier de Boissoudy wanted to represent these things whose nature exceeds the limits of our intelligence and our reason. In the sacred setting of the old sacristy of the Collège des Bernardins, discover his black and white interpretations of the mystery of the invisible presence, which it reveals in the present of a landscape, of a contemporary scene or at the heart of a biblical scene. Through large figurative canvases, his use of dark inks reveals the presence of light, and perhaps something deeper.