This quest is initiated by Krindal on an island in the icegill area at 579, -38, -1632 . It is the access quest for Drayek's Chamber in Permafrost. You must speak Krombral to receive this quest, which can be learned by completing the Words of a Giant quest.
You must slay five rare spawns in Permafrost to obtain their pieces. They are:
Commander Keg's Key - Commander Keg (southeast corner of courtyard) at -95, 0, -130