Given the task of escorting an emissary from the Emperor Charlemagne, Sinbad is dismayed when his dhow is attacked by Northmen-savage pagan pirates who sail the northern seas, slaughtering and pillaging. But these warriors, and their queen, Helga Hammerhand, have a different mission-one for which they require Sinbad's services, willing or otherwise. As a prisoner, Sinbad joins them on a voyage into the frozen north, far beyond their own country of Frostheim, in a desperate search for the land at the back of the north wind. Through seas of monsters they sail, but once the channel of the sea serpents is passed, what horrors will they find in the lands beyond? And will Sinbad ever escape? Or is this his final voyage?