"Quod est in speculo ut in subiecto." According to medieval philosophers, being in a subject is an insubstantial way of being that does not exist in itself, this one is in something else. In this short film, the nature of the images is questioned, particularly the one of the reflected corpses in the mirror. What is their nature? How can a mirror with his two-dimensional character transliterate three-dimensional images? The essence of the image, visible on the mirror surface, is a continuous formation in absence of tangible substance. A tribute and at the same time a contestation of J. Cocteau.