Getting the Destiny 2 Necromantic Strand can be a confusing step in the Essence of Brutality quest because it requires finding the Hall of Wisdom. But it's worth doing for the Loud Lullaby legendary hand cannon. Similar to other weapons found on the Moon, Loud Lullaby has charms that illuminate when you're near a Nightmare—special hidden enemies you have to kill to complete the final quest of Shadowkeep.
Like the Horned Wreath (opens in new tab) and Captive Cord (opens in new tab) items found from other quests similar to Essence of Brutality, the Necromantic Strand is tucked away in an easy-to-miss section of the Moon. Fortunately, this guide is going to show you exactly where to go.
Destiny 2 Necromantic Strand and Hall of Wisdom location
Destiny 2 Captive Cord (opens in new tab) - Essence of Failure
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Destiny 2 Fangs of Shun'gath (opens in new tab) - Essence of Rage
Finding the Hall of Wisdom is actually quite easy once you know where to go. Start from the Sanctuary spawn point and head left, following the trail until you eventually arrive at Archer's Line. Once in Archer's Line, the entrance to the Hall of Wisdom is found in the northeastern corner and is guarded by a few Hive.
Enter the cave and follow it until it opens up to an expanse with ledges that you can drop down onto. You want to look for the white light at the bottom that signals the passageway to the Hall of Wisdom. You'll know you're headed in the right direction almost immediately as the Hall of Wisdom name pops up on your screen.
Once you enter the Hall itself, you'll see a large glowing chandelier to your right. Approach it and a quest marker should appear pointing to the location of the Necromantic Strand.
So you can't miss it: The Strand is laying at the base of the broken structure encircling the chandelier on the far side from where you entered the Hall of Wisdom. The second image above will show you where to look. With the Necromantic Strand in hand, the two remaining steps of the Essence of Brutality quest are easy-peasy.