A Harsh Climb is the only mission in the Himalayan section of the gsme which comes after Gizeh. Here is 2 part video should you wish to follow it
It is linear with a bit of stealth and 1 puzzle- crack the code.
The easy way is for the code is to put in 3666 to the door, however if you want to solve yourself you need the coding machine in the corner.
You will find a clue as walk in JOGM.
Enter the cog wheels in the left hand side and interact above the decoder to close it.
Tyeo in that code (you may need to open and .ove the wheels around, I found it easier to put the all I'm and find one of the letters)
This will reveal the word BLUT. On kne of the clipboards is this word with code 3666.