The Sea Devils have risen against Tir Nan Og, the Land of the Young, and Sláine, once the first High King of Ireland, must protect his tribe against this new tide of evil.

Leading the demons is Moloch, a hideous Formorian lord, bristling with swords and driven by a perverse hunger for human suffering. Fighting alongside his warrior wife Niamh, Sláine must drive back the demons or pay a price too terrible to comprehend...