The epic first instalment in a sequence of novels set at the end of the Roman Empire, during the reign of the Emperor Constantine

Aurelius Castus believes his glory days are over. He used to be a soldier in the elite legions of the Danube, and now he is stuck in Britain's provincial backwater. But history takes a hand when the king of the Picts, the savage people beyond Hadrian's Wall, dies in mysterious circumstances, and Castus is selected to command the bodyguard of a Roman envoy sent to negotiate with the barbarians. The diplomatic mission ends in bloody tragedy. Castus and his men are soon fighting for their lives and the legionary discovers that nothing about his doomed mission was ever what it seemed.