If you try to complete the Fourth Horseman Quest in Destiny 2 you will be looking for the Legendary Lost Sector of the Quarry. I have bad news for you, I'm afraid. Legendary Lost Sectors are not like normal Lost Sectors, and you cannot get to them. Although the usual Quarry Lost Sector is in the Sunken Isles on the EDZ, you cannot access the Legendary version from there.
The only way to access a Legendary Lost Sector is to interact with the console in the Seraph Bunker on the EDZ. To deliver all the bad news early on, Legendary Lost Sectors also work on a rotation, so if you're trying to get into Quarry today, you won't be able to. The career is not in rotation today and you will have to check again tomorrow to see if it is active or not.
Remember, you also need to be around 1000 Power for those Legendary Lost Sectors, so make sure you're close or bring some friends with you. Sadly, it looks like Bungie has decided that they need to spend some time in the quest for the Fourth Horseman.
How to access legendary Lost Sectors
For people who haven't activated their Seraph Bunker on the EDZ, we'll quickly walk through the procedure to access Legendary Lost Sectors.
Legendary Lost Sectors actually look a lot more like adventures, and you have to start them the same way. The first thing you will need to do to gain access to the Lost Legendary Sectors is to complete certain stages of the Raising our Defenses quest. You will need to play until you activate the Seraph Bunker. Just play through the quest until you reach this point.
When you have activated the Seraph bunker, you will notice a console to the right of the room. This is where you can launch the legendary Lost Sector. These are very difficult missions, and you may not have enough power to survive them at the start of the season, so be warned.
Completing a Legendary Lost Sector will grant you much-needed Warmind bits that you can use to upgrade your Seraph Bunker.
