What is the enduring power of mimesis? What hold do paintings that mimic perception have over our imagination? This essay analyses Hans Holbein the Younger's portrait of The Ambassadors to assess its magic both for ourselves in the present and for those who first beheld it. The very structure of the work, its facture, is invested with an iconic vitality that we often overlook. Its surface is alive with a thoroughly medieval sense of pictorial presence that Reformation image theory sought to destroy. The shadow of iconoclasm that hangs over these pictures lends them a particular poignancy, for the illusionism that once endowed the dead with afterlife continues to invest them with remarkable ontological power. The to-and-fro of our perceptual encounter with the world insists that we ascribe such paintings an agency that exceeds our own.