###Inside the Mountain puzzle and Ascend the Mountain
This quest will have started as you made your way through the thick black smoke and ascended the exterior stairs of the Mountain. After reaching the top of the stairs, move to the left and hang from the railing. As you move upward, follow the gold highlighting and the button prompts.
As time goes on, you’ll get closer and closer to the entrance, which will be marked by a massive wooden door and additional puffs of dark smoke that need to be cleared away. You’ll find yourself in a room with another sand bowl and a large statue of a stag if you manage to pry it open and head inside.
In order for you to proceed with the game, there are two Crystal sockets that need to be filled. The one on the right is organised, whereas the one on the left is devoid of content. After that, keep to your left and enter that side passage. You’ll come across a few Draugr in that area, as well as a Crystal perched high above you on some combustible wooden planks (we actually destroyed those planks in the middle of the fight without even realising it, but the Crystal is easy to retrieve!
You may have noticed some strange red sap blocking the path in that left-hand tunnel; you’ll be able to clear this later on but for now, ignore it. Carry the Crystal back to the socket. Note that you will be able to clear this later on but ignore it for now.
Atreus must first destroy the two Crystals in this area using his bow, and then they must proceed to the lever in the region’s centre and pull it. The ground is now covered in illuminated runes, which, when the level is lowered, will align themselves to reveal the solution to your problem: the way forward is not straight ahead, but rather to the right.
You should now push the doors that have just opened to the right and continue through, providing light by shooting the blue Crystals as you go. Continue to make your way through the tunnel until you reach a new area.
###Traverse the Dark Caves
After picking up a toppled pillar, the very first thing you will see is a Revenant, along with a few Nightmares following it. First, you should concentrate your attention on the Nightmares, and then, after stunning the Revenant with Atreus’ arrows as usual, you should begin to whittle it down until it is dead.
There are a few ways to proceed from here, and there are also some mysteries to be uncovered. To begin, while you are on the first bridge, look up to see some discs holding some hanging buckets. If you hit those discs, the buckets will drop, and you will be able to retrieve Hacksilver.
The next step, while you are still on the bridge, is to head forwards past the large hole in the floor on the left, then turn back the way you came and look down through the hole to see an Odin’s Raven that you need to whack with an axe throw.
As you proceed forward, you will come upon an ascendable ledge directly in front of you, a spinning totem bearing a rune just to the left of where you are standing, and an old wooden cart to the right of where you are standing. By destroying the cart, you will gain access to a small side path that leads to a coffin chest. This path can be reached by following the side path. Please reappear just a moment later.
After you have vanquished any foes that appear at the top of the ledge, return to the right side of the screen and climb the ledge. You should now be able to see a Crystal beneath the right-hand fork. Atreus can use this Crystal to create a light bridge by shooting it. Jump to the ground, traverse the gap, and seize the treasure from the coffin.
Once you’re back on your feet, hang a left. A Nornir rune chest and a Lore Marker are the two things that need to be unlocked in this location. First, the Lore Marker: shoot the wooden planks that are just ahead to the north-west that hide a Crystal to form a bridge, then splinter the remaining planks to reveal the Crystal.
Just before you begin the ascent, hang to the right of the bridge to locate an additional Crystal on the ground, hidden behind a rock. Bring that up the bridge; the Nornir Chest is just ahead of you, but we’ll return to that in a moment.
To access the Lore Marker, you will need to travel across this stone bridge to the South-West, defeat any Draugr that appear, and then insert it into the socket in the room at the very end of the level.
To locate the Nornir rune chest, you will need to travel back to the opposite side of the bridge. Runes that you need to read are painted on the wall behind it; use the Crystal light to illuminate them, then move in close to Atreus so that you can read them together.
You have to go to those totems and spin them so that the runes on them reveal the ones that are marked here in order for it to be unlocked:
First, head down the light bridge and turn around so that you are facing it. There will be a wheel on the right that you can spin to locate the R symbol.
The next step is to descend the short marked ledge that you scaled earlier in order to reach the one that you first noticed and continue doing so until the letter N appears.
Now return to the top of the light bridge, turn left onto the stone bridge, and when you are almost at the end of the stone bridge near the lore marker, look up and to the left to find the third bridge. You only need to press that button to proceed to step B. (You can also reach this, albeit with some difficulty, from the lower level, as we did just about all that we could).
Another Horn of Blood Mead can be found buried within the Nornir rune chest.
Now, head back down the light bridge and hang left. When you reach the back wall, hang right; this will lead you to some more breakable wooden planks that are hiding a room with a dead soldier and a new collectible artefact for the Bottoms Up set.
Come back out, make a right turn, and head in the direction of the north-west until you reach another corridor that will lead you out of this area. You’ll find yourself hunched over in a passage filled with dead people who were killed by traps, and you’ll eventually emerge from behind the statue of a stag that’s located near the entrance.
After you have read the runes on the back of the statue, open the hacksilver chest that is around the other side of it, and then smash the wooden planks to the east, you will be able to access a room that has a scroll called The Serpent lying on the floor of it.
Return to the main area where the statue is located and activate the large doors located to the north-east to proceed. In front of you is a Draugr, and to the left is that red sap that you were unable to get around earlier. So keep your chin up! Continue to illuminate Crystals along the way and defeat any Draugr that you come across.
You will eventually arrive at the conclusion, at which point there will be some wooden panelling on the right and a coffin chest directly behind it. There is a low entrance just to the right of that, and you can crawl under it to get to the coffin on the other side of the room.
Return to the entrance and then climb the markings on the cliff in front of you; there are additional runes for Atreus to read along the way. When you reach the top, kick the chain down after you in case you need to go back.
Continue along the stony path in front of you, and as you go, smash the wooden stuff on your left to expose a chain that will lead you down to a lower platform that has a chest containing hacksilver on it.
You need to climb back up, then at the top of the path there is a contraption that you can use to open the door and proceed to the next area, which is full of puzzles.