Update: Bungie has made the Quarry available, so you can just head to the Seraph Bunker on the EDZ to start it up.
If you are trying to complete the Fourth Horseman quest in Destiny 2, you will be looking for The Quarry Legendary Lost Sector. I have some bad news for you, I am afraid. Legendary Lost Sectors are not like normal Lost Sectors, and you cannot travel there. While the regular Quarry Lost Sector can be found in the Sunken Isles on the EDZ, you can’t access the Legendary version from there.
The only way to get to a Legendary Lost Sector is by interacting with the console in the Seraph Bunker on the EDZ. To deliver all the bad news early, Legendary Lost Sectors also work on a rotation, so if you are trying to get to the Quarry today, you won’t be able to. The Quarry is not on today’s rotation, and you will need to check again tomorrow to see if it is active or not.
Remember, you also need to be around 1000 Power for these Legendary Lost Sectors, so make sure you are close or bring some friends with you. Unfortunately, it seems that Bungie decided some time-gating was needed on the Fourth Horseman quest.
How to get access to Legendary Lost Sectors
For people who haven’t activated their Seraph Bunker on the EDZ, we will quickly run through how to that so they can access Legendary Lost Sectors.
Legendary Lost Sectors are a lot more like Adventures, and you need to start them similarly. The first thing you will need to do to get access to Legendary Lost Sectors is to complete some steps in Raising our Defences quest. You will need to play until you have activated the Seraph Bunker. Play through the quest until you reach that point.
When you have the Seraph Bunker activated, you will notice a console to the right of the room. This is where you can launch the Legendary Lost Sector. These are challenging missions, and you may not have enough Power to survive it at the start of the season, so be warned.
Finishing a Legendary Lost Sector will get you some much needed Warmind Bits that you can use to upgrade your Seraph Bunker.