AD 406. Abandoned by his friends and hounded by his enemies, Roman cavalry commander Marcus Flavius Victor is forced to flee an increasingly fractured Britannia with a small band of loyal warriors. His journey takes him north through the stormy, pirate-infested seas of the Mare Germanicum to Saxonia, where his son Brenus has languished as a slave for six long years. Marcus is able to rescue him but at a terrible cost. Further disaster threatens when his escape route is blocked, leaving the Britons trapped in a strange land with enemies seemingly at every turn. Their only salvation seems to lie with Marcus's old comrade, General Stilicho, beyond the far Danuvius, still within the sanctuary of the Empire. To get there will mean a journey of many hundreds of miles through the dark heart of barbarism - and, unknown to Marcus, Stilicho has troubles of his own. His influence with the Emperor Honorius is diminished, and a great people are on the march, leaving a sea of bones in their wake. Savage Radagaisus, king of the Ostrogoths, has promised his subjects all the riches of Italia and a new future. As he battles his way towards safety, Marcus stumbles across a secret which could decide the very fate of the Empire. But who can he really trust, and can he reach Stilicho in time, with his every step dogged by a son who wants him dead?