###Thamur’s Corpse puzzles and the Frozen Lake puzzle solutions
You will make your way up from the previous area onto the edge of an area known as the Frozen Lake. Thamur’s Corpose will be laid out in front of you at this point.
Get a hold of one of the Chisel’s pieces.
Before continuing, there are a few things that need to be done in this area, including the closure of a Realm Tear, the unlocking of a rune gate that leads to a coffin chest that contains a legendary enchantment, and the vanquishing of some challenging foes.
To begin, eliminate the few Wulver that are scattered across the front of you to create some breathing room for yourself.
After that, you should head south. You will notice a few things, including a Lore Marker inset into the side of a stone structure, a blue crystal covered in red sap, and just to the right (West) of those, a marked spinning pannel for you to throw your axe at, which will raise up a spinning rune totem.
To begin, you should consult Atreus about the lore.
Then, proceed to check out the locked gate to the North, which has three Runes above it, in order to determine what you need in order to open it: the letter E, a R facing in the opposite direction, and the arrow pointing upwards.
The first spinning rune totem can be found just to the left of the entrance gate. You’ll see the upside-down R if you hit it twice.
After that, head over to the first totem you saw, close to the panel that was marked with the Lore Marker. Raise the totem by repeatedly hitting the panel with your axe throws, and then throw your axe at the spinning totem just once to reveal the E.
The final spinning totem is hidden by some sap a little further along the northwestern side of the area. It is in the middle of the area. In order to release the sap, you will need to retrieve some red crystal from the tree stump on the south-eastern side of the room, then hurl it at it and detonate it using a Shock Arrow as you normally would. You only need to hit it once to reveal the upwards arrow Rune, and then the gate will open for you.
It may be difficult to get to, but it is well worth the effort because the chest that lies beyond the gate contains a Legendary Enchantment that increases the damage done by your throwing axe. In addition, the chest contains a pile of Hacksilver.
The crystal that was covered in sap comes up next. Take a few more of the red crystals that are in the stump, toss them at the sap, and then shoot it with a Shock Arrow to cause it to drop a blue crystal. Bring that to the socket in the northeasternmost part of the lake, and then insert it there to open a Realm Tear. Interacting with it will reward you with a rare item known as Dust of Realms.
At long last, there is a tomb to loot in the middle of the lake, and an Ice Ancient can be found nearby. It is up to you if you want the practise (and rare loot) or if you want to igore it and press on. The sleeping ancient will awaken if you touch it, so it is up to you if you want to touch it.
When you are ready to proceed, follow the waypoint to the north-east. This will take you further. Soon after, you’ll find that you’re up against more new foes, which are known as Ice Nightmares. After defeating these foes, you’ll have to climb under the rock behind them in order to reach the Head of Thamur.
###Head of Thamur
This new region is quite intimidating; after all, you are standing right in front of a giant’s severed head. However, you won’t have much time to reflect on its magnitude because you will soon be thrust into a difficult and fairly extensive fight!
Find a way to de-ice the situation.
Enemies! A horde of Druagr and, what’s more important, not just one but two Ogres appear at the same time. The most effective strategy is to use your Spartan Rage ability whenever you have it and then concentrate on killing an Ogre. By climbing up onto the back of one of these, you will be able to direct the massive amount of damage that it deals to the other foes.
If you can use that one Ogre to take down the other Ogre and as many Draugr as you can while you’re at it, then hopefully you won’t have to worry about them anymore. Keep in mind that Atreus may also have access to various runic summons, which are an excellent method for maintaining order among a large number of adversaries.
Talk to Sindri
The appearance of Sindri was completely unexpected. Have a conversation with him to find out that Dwarves have the ability to turn invisible (this will explain a lot), and then visit his shop to improve anything that needs it before continuing.