Archivum Data Disc and its Heroic mode equivalent: Heroic: Archivum Data Disc start the quest chain required for access to Algalon the Observer. It follows the vein of the Malygos attunement, where only one player in the raid needs the key to gain access to the boss. The item that starts this quest requires the completion of the Assembly of Iron encounter by defeating Runemaster Molgeim or Steelbreaker last (Medium difficulty and Hard mode, respectively).