For one of the stages of The Quest for the Exotic Lament Sword, you will need to find an abandoned bunker in the Eventide ruins. It’s a lot easier to do than you might think, as the abandoned bunker is actually Bunker E15, the Lost Sector that is in the area.
To get there, spawn at the spawn point near Variks at Charon’s Crossing, then get on your sparrow and start moving to the left of Varik’s little hideout. Just keep your head straight along the road with no major left or right turns at intersections until you reach a tunnel. This tunnel will lead you to the Eventide ruins.
When you get there, you’ll notice a massive building in front of you with a small door to the side. Enter through this door and turn right. You will see a broken space in the wall with icicles on it. Jump into space, then descend to the other side.
It is actually quite a difficult place to find. You’ll need to go to the Eventide Ruins area, then head to the left side of the huge building in front of you if you’re coming from Cadmus Ridge. You will find a door at the top of the stairs and be able to head inside. Turn left and you will see a break in the wall. Jump in there and follow the tunnels to get to the Lost Sector. The Lost Sector of Bunker E15 has a recommended power level of 1210.
To complete this step of The Lament quest, you will need to go to the end of the bunker, kill the boss, then open the cache. When you do, the next stage of the quest will begin.