The following chapter provides a detailed description of the gameplay during Grave-Hoard. You will find tips that can help you complete the quest in the most effective way possible.
The quest will be added to your journal right after you complete Maker's End. Your task will be to take Aloy to other ruins to continue her research.
On your way to your destination, you will come across a group of cultists and some corrupted machines. Use fire to get rid of them. Go deeper into the ruins. You will come across more cultists in the first chamber. One of them has a canister on his back - hit it to set it on fire. The remaining enemies should not cause too much problems. You will come across some recordings that you should play. Now follow the only available way deeper into the shelter.
You will reach a flooded chamber. You will be able to proceed via handles on the wall. Use them to climb up and move forward. On your way, you should pay attention to the radar, as it will show the location of recordings and notes.
Collect all the notes and go deeper into the ruins through the presented hole in the floor. It will lead you to another pair of doors. Let Aloy investigate it, and she will realize that the power was switched off. Go to the chamber next to it and fix it.
To turn on the power again, you will have to adjust switches on two levels of the ruins. A hint on the correct configuration can be obtained by using Focus to scan the device, located on the left from the switch. The lower configuration may cause more problems as you will need to play the recording, located by the coding machine.
Upper floor - from the left: up, down, left, right.
Lower floor (from the recording) - from the left: up, left, right, down.
Lower floor - from the left: up, up, down, down.
Once this is done, get back upstairs and continue to explore the ruins. You will run into more Cultists in the next chamber. You will have to eliminate them before you can move forward. It doesn't matter how you will achieve it but the longer you stay hidden, the more med pouch you will save for later.
Once you defeat the last enemy, proceed deeper into the ruins. In order to get there, you need to go across the metal bar  and jump towards the rocky shelf  in front of you. Once you get there, you will have no problems with locating handles that can be used to climb  on the opposite wall. Disperse and jump on it.
On your way, you can play many notes but eventually you will reach the room presented in the screenshot. Use the console to proceed with the quest. Use the corridor on the right, and get to the other part of the shelter.
There will be some cultists on the other side. This time a Deathbringer will be with them. Note that the platform you are standing at will break after a single shot from the machine and Aloy will die from fatal fall. Duck and run right. You will find a handle that Aloy can use to slide down the rope.
If you were not detected by the machine so far, know that it will spot you as soon as you kill the first cultist. There are no Cultists' leader, so most of them should die after a single strike with the spear. The important fact is that the Deathbringer will pay little attention to its own allies and may hurt them as well.
Depending on your resources, there are two ways to fight with the machine. You can set its torso on fire and strike the machine with electricity if you have enough resources to create arrows. You may also tear separate combat elements by aiming at them. We recommend the cannon on its right shoulder. It's basically immune to strikes, so you won't tear it too fast, and you will deal significant damage thanks to it. You may also aim at other parts, or even combine both strategies. Remember to dodge a lot, especially when the Deathbringer uses rockets.
Collect the items that were scattered around and reach the door marked by the indicator. There is another room on the other side with a hidden diary and another console in it. Use it to proceed with your quest. Leave the Grave-Hoard via the elevator shaft.
Sylens will appear at the top. Speak with him to begin a new quest and complete the existing one. Finish the dialogue and a new quest will appear in your diary - To Curse the Darkness.