Disaster! Flavia Gemina’s father’s trading ship is wrecked. Soon after he arrives home barely alive, creditors try to seize the house, giving them only a day to find enough money to pay the debt. Flavia, her father, Jonathan, Nubia, and Lupus take refuge at a country estate where they learn of a sunken treasure ship in the dangerous waters nearby. Lupus is sure he can retrieve the cargo. But their enemy, the slaveowner Venalicius, is after the treasure too.