Kil'jaeden cast Ner'zhul's icy cask back into the world of Azeroth. The hardened crystal streaked across the night sky and smashed into the desolate arctic continent of Northrend, burying itself deep within the Icecrown glacier. The frozen crystal, warped and scarred by its violent descent, came to resemble a throne, and Ner'zhul's vengeful spirit soon stirred within it.