You'll need Destiny 2 Withered Plume to finish the Essence of Obscurity introduced in the Shadowkeep expansion. This awards the submachine gun Every Waking Moment, which at this point is just an item for your collection since it's been permanently sunset (that is, power capped). Still, it's worth polishing off the Essence quests for completion's sake, so here's a quick guide on where to find the Circle of Bones and collect Destiny 2 Withered Plumes.
How to find the Circle of Bones
The Circle of Bones is basically the underground hub of the Hellmouth depths. All the main paths lead to it, and it leads off into everything else. As such, you can reach the Circle of Bones through any of the three main paths, but we prefer the path found northwest of the southern landing zone on the Moon. Just take the west path and head slightly north when you reach the open area, then go through the old lab at the top of the hill.
From here, keep descending and going straight - past the Hall of Wisdom - and you'll reach the Circle of Bones. When you come out, you should see a big hole in the wall on the opposite side of the Circle. The Destiny 2 Withered Plumes are to the left of that hole, so hug the railing on the left and follow it counter-clockwise. You can ignore or kill the Hive along the way.
You'll quickly come to a dead-end with a small bit of railing off to the side. The Withered Plumes will be lying on the railing. Snatch 'em up and you'll be set to finish off your Essence of Obscurity.
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