Libertus has an important order to fulfil for Quintus Severus, who has commissioned a new mosaic. But when Lucius, the pie-maker, is found dead in Libertus' workshop, and Libertus' faithful slave Minimus is missing, he is once again dragged into a criminal underworld. Can Libertus find Minimus, clear him of the murder, and discover who really killed the pie-seller, and why? The omens aren't looking good . . .