Destiny 2’s latest update is now live and it’s introducing another wave of content tied to the Black Armory DLC. One of the most important additions is the fourth and final key to the Mysterious Box that users received way back at the start of the new season. Unlike the other keys, this one isn’t directly tied to shooting drones in the fourth forge. Instead, users will need to hunt down the Black Armory Key Mold first and then complete a series of quests.
Thankfully, getting the mold is really simple, especially since the Niobe Labs completion is no longer required to visit the Bergusia Forge. In order to obtain the Black Armory Key Mold just visit Ada-1 and she will hand it to you. We aren’t sure if you need the other keys for the Mystery Box to have Ada-1 offer this up. However, she is your one and only source, so make sure to check with her the next time you load in.
Once you have it, go to the Leviathan (It’s located on the Nessus map now) and enter the underbelly via the secret code. After this, just search the area until you stumble across the Watcher robots. These are the sentries with light up eyes that scan specific rooms. Just kill them to obtain Watcher Lenses and progress to the next step of the quest.