This is number four in Nick Brown’s Agent of Rome series and it shows a continuing improvement and deepening in the author’s work. The key to the series is the complicated relationship between its three main protagonists: Cassius Corbulo, a young Roman patrician and agent of Imperial Security; Indavara, an ex-gladiator who has lost his memory of life before the arena but who is now his bodyguard; and Simo, Cassius’s slave. Their unfolding relationship, and the ramifications of the very unequal levels of power each man has, is played out against an exciting plot – but the plot is only exciting because the reader had become deeply invested in these three men, and wants to know how things turn out for them. Excellent.