Our Hell is Us Plains of Mist Door Puzzle Guide will tell you how to open the round door with four symbols that leads to the Temple of the Fallen and open the path to the Keystone of Ecstasy.

Hell is Us Plains of Mist Door Puzzle Solution
The Hell is Us Plains of Mist door puzzle solution will open up access to the Temple of the Fallen, the penultimate area of the game. It's jam-packed full of puzzles, but you'll have to open the front door first.
The outdoor area of the Plains of Mist is fairly small compared to some of the other Locations on the map. There are a few enemies to fight and a few items to be found (including a Research Item), but otherwise, it seems like a fairly innocuous set of ruins.
One of the features of these ruins is four symbols prominently displayed at several locations. Each symbol is also contained within a specific geometric shape. The puzzle door in the Plains of Mist, in turn, has a combination lock where symbols can be rotated into fixed slots with four different shapes.
Simply put, the solution is to observe the symbols and the shapes surrounding them, and then rotate the wheels on the combination lock so they line up with their associated shapes.
Here's what that looks like:

The correct order of symbols are, from top to bottom:
- Pentagon / Dagger
- Square / Diamond
- Circle / Sun
- Diamond / Eye
Line up all four of these symbols and you'll be able to enter the Temple of the Fallen, a long-dead breakaway religion of Hadea and the location of the Keystone of Ecstasy.
Mind, getting past this first door is just the beginning — you still have a few more puzzles ahead such as the Trial of Lies and Truths Puzzle and the Gorge of Our True Sacrament Puzzle.
We're at the end of our Hell is Us Plains of Mist Door Puzzle Guide, but there's still a bit more game to go — check out our other guides below!