In the Altes Museum in Berlin there is a circular painted panel, tempera on wood, roughly 30 centimeters in diameter, made in Egypt around 200 AD. It shows a Roman imperial family in full regalia: a bearded emperor in the upper right wearing the jeweled diadem of the Severan dynasty; his wife beside him on the upper left, dark-eyed and elaborately coiffed; a young man below them in the center wearing his own smaller diadem. A fourth face occupies the lower left — or rather, a fourth face should occupy it. What is there instead is bare wood, scratched down to nothing by something sharp, the ghost of a face removed with deliberate force at some point after the panel was painted. The family portrait has three people in it. It was made to have four.