Explore Savathun's throne world in Destiny 2: The Witch Queen for a while and you might stumble upon some special, glowing Hive enemies, or investigate the curious corpse of a dead Scorn chieftain. These interactions, if you complete them, will eventually lead you to a special secret mission called Memory Alembic. Completing it is necessary to unlock all the secrets in the throne world and complete the Witch Queen's Triumph seal, but you'll have to puzzle out how to go about it on your own.

Or, you would have to puzzle it out, but we're here to help. Though the Memory Alembic mission is obtuse, solving the case of the dead Scorn isn't too difficult once you know where to look for clues. The mission will have you hunt down and destroy several special Hive Executioner enemies, which earns you a Triumph and a special resource called Qualichor. You need a fair amount of Qualichor to advance the quest, and it's not immediately clear how to get it.

Below, you'll find everything you need to know about Qualichor, Hive Executioners, Hive Inquisitors, and the Memory Alembic quest to complete it.