At the Empire’s northern edge lies Alba: strange, savage, unconquerable. Twenty years ago this rain-sodden island defeated a huge Imperial army. Now the Empire returns. Disgraced generals are looking for vengeance. Their forces are accompanied by three promising Tribunes: warlike Bellacon, intelligent Convocus and the joker in the pack, Cantex. As the armies journey into the interior, it becomes clear all is not as it seems. Beyond the realms of the Emperor, treachery is never far away. The invasion will be harder than anyone could have imagined. Can the Tribunes triumph against the odds? Or is this the very limit of Empire?