A fragile peace governs the kingdoms of Wessex, East Anglia, under the rule of the late King Alfred's son, King Edward, and Mercia, under his daughter Aethelflaed. Uhtred, her formidable champion and greatest warrior, controls the northern parts from the strongly fortified city of Chester. But no one can prepare them for the storm that is about to descend. The Northmen, allied to the Irish, come in force under the cover of night, up the Mersey, perhaps to attack Chester, perhaps to rage and pillage through Mercia, perhaps to take the troubled kingdom of Northumbria. They are led by the terrifying Viking warrior Ragnall Ivarson, a fierce fighter and ruthless leader. He and his army are formidable enough but worse still, his brother is married to Uhtred's daughter. With his passionate determination, Uhtred will stop at nothing to take back his corner of Northumbria and secure the future of Bebbanburg. But for Aethelflaed and the Mercians, doubt must arise to where his loyalty lies. In the struggle between family and loyalty, between oaths given and political demands, there is no easy solution. And the clash between the Vikings and the Saxons will resound across the land.