Lumbered with working alongside reptilian Chief Spy, Anacrites, Falco has the perfect plan to make money: he will assist Vespasian in the Emperor's "Great Census" of AD 73. His potential fee could finally allow him to join the middle ranks and be worthy of long-suffering Helena Justina. Unexpectedly confronted with the murder of a man-eating lion, Falco uncovers a bitter rivalry between the gladiators' trainers. With one star gladiator dead, Falco is forced to investigate and the trail leads from Rome to the blood-soaked arena in North Africa.