Lumbered with working alongside reptilian Chief Spy Anacrites, Falco has hit upon the perfect plan. He'll offer his services to Vespasian and Titus in conducting the "great Census" of AD 73 as a tax collector. If he does well, his fees will finally allow him to join the middle ranks and wed his long-suffering companion, Helena Justina. Meanwhile, Falco needs to trace a relative who has eloped, and he has a crazy plan for finding an extinct herb.As Falco pokes around, he learns about the death of a much beloved lion, then uncovers a bitter rivalry between gladiators' trainers. When a star gladiator ends up dead, Falco is forced to investigate. The trail leads to Tripoli, where the killer has escaped and where Falco meets up with more danger.