Legionaries Cato and Macro have forged a bond that has survived war, rebellion and torture. Yet nothing has prepared them for a daunting mission on the deadliest battlefield of all: the bloody streets of Rome. It is AD 51 and traitors threaten to plunge the Empire into bloody chaos. No one can be trusted. The emperor has ordered Cato and Macro to join the Praetorians, his private bodyguard. Their deadly mission is to work undercover and root out the traitors before Rome tears itself apart. As the true scale of the corruption dawns, they realise they are facing terrifying odds. Two men against many, in a desperate race to save not only the Empire, but each other...