The term "ekphrasis" is indisputably problematic. In fact, depending on which definition one might use ekphrastic processes can either be broad, that is extended to any type of description as it was taught in rhetoric treaties during antiquity, or according to its modern definition circumcised to literary representations of works of art. Since ekphraseis are a key feature of Huysmans's work, this study strives to explore their scope through describing the sacred art in the so-called "catholic novels" Huysmans wrote after his religious conversion and the Church's representation that stems from them. This study focuses on two forms of religious art: the plainchant and the architecture. Based on a broad theoretical frame ranging from ekphrasis and hypotyposis figures of speech to intermediality, the study shows that the medieval Church is considered as quintessentially a pluri-medial entity or as Wolf puts it, a "syncretistic medium". Thus, it seems possible to establish a connection between this image of an ideal Church and the notion of Gesamtkunstwerk. Last but not least, this depiction which arises from Huysmans's work sheds light on a broader societal phenomenon that occurred in the transitional period which was the late 19th century, namely a strong interest in medievalism.