There's a new and rather complicated Enigmatic Mystery called The First Rule in Destiny 2 this week as we visit the Debris of Dreams. You'll want to have Sight: Frequency Echoes unlocked before jumping in as well as your usual true Sight and Barrier Breach abilities. For this challenge, you'll need to find three Scorn passcodes to unlock a chest, so let's see where to find them.
Destiny 2 The First Rule: Where to find the Scorn passcodes
To open the chest and unlock this Enigmatic Mystery, you'll need to find and kill three Scorn bosses. After you've aligned the second beacon, head to The Encampment via the vertical pathway directly in front of the beacon. Jump up until you find the locked door, which you can open by taking out the enemies and interacting with the interface.
When you enter the room, you'll face the first boss, Akaskis the Listener. You'll also find the chest locked behind a barrier and three terminals on the floor. Once you've dealt with the boss, interact with one of the terminals to input the passcode he drops.
From here, you'll see a path blocked by a barrier. Use Barrier Breach to clear the way. Carry on until you encounter a Safe Passage totem, so interact with it before heading up the stairs and outside. Here's where things get easy; a waypoint should now appear, so stick to the right and head towards the next boss.
Use Barrier Breach to enter the building and face off against Kaaskis, the Hungerer. Once you've got the next Scorn passcode, head back the way you came to the chest room to input it. To find the third boss, you'll want to exit the chest room via the way you came in from the second beacon, and head over to The Ruined Outpost. It's near the entrance to the Shattered Realm.
There's a big spinning contraption on the main island, so jump down between the rotating arms and have a wander around until you spot Siirnak, the Deepwalker. Defeat him, get his Scorn passcode and head to the chest room for a final time. Once you've inputted the last code, the chest will unlock and you'll complete The First Rule Triumph, as well as get some Enhancement Cores.