Falco is on an undercover mission to Roman Germany, where there has been trouble with the natives. There he must exercise his doubtful diplomatic skills on Civilis, a one-eyed Batavian rebel chieftain. He must also persuade a sinister tribal prophetess to stop her incessant rabble-rousing. But every rustling leaf heralds the approach of ancient ghosts, headhunting tribesmen, or primeval animals. First published in 1992. Fourth in the series.