"Directly east of the stairs you should find a low wall - climb over it." This is from the Mourning's Ends Part II quest guide. Under step #5 it says this; The Yellow and Cyan Doors I believe. The link that takes you to the map of the fourth door is where the quote is from. It's correct in the original guide it's correct, but on this link to the map it says east. The direction is actually west not east. Just letting you know, thanks for looking. :D

In the Mourning's Ends Part II quest guide, the link that pops up with a display of what the lights and mirrors should look like for the fourth door contains inaccurate information. Below the image it says that you should look east of the stairs when actually it should say west. In the actual guide it does say west, but in this link it says east. Just letting you know :D