It's Gebruary, AD 80. The fever that started in Ostia is sweeping through Rome. Jonathan's father, Doctor Mordecai, is summoned to Rome to bring his healing skills to the plague victims. It's a dangerous place to go, but Jonathan, Flavia, Nubia and Lupus are required to accompany him. The Emporer Titus believes that they can help him find the mysterious enemy who seeks to destroy Rome.