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...