The powerful necromancer Nagash, having suffered defeat on the battlefield at the hands of the priest kings, is forced to lick his wounds in the mountains of Nehekhara. Over time he rebuilds his strength and finds new allies in the skaven, mutant ratmen that live beneath the earth. In his new lair of Cripple Peak, the necromancer discovers something dark and powerful - warpstone. Coveted by the skaven, this magical rock could make the evil Nagash unstoppable.