Note: Clicking a cell door will tell you what kind of key it requires.
Speak to Druzzil Ro at ( 45, -67, 13 ) Copy/waypoint 45, -67, 13
either tab to her and press h, or kill an enforcer (in one of the cells) for the Justicarium Key to her cell
Obtain a mithril cell key from a green shiny at ( 28, -67, 9 ) Copy/waypoint 27.95, -67.02, 8.59, then unlock the cell door at ( 21, -68, -5 ) Copy/waypoint 20.53, -67.51, -5.46
Kill Balgros at ( 22, -68, -26 ) Copy/waypoint 22.02, -67.60, -26.17 to obtain a feyiron cell key.
If you hug the east wall, you can get back to the corner and fight Balgros there without aggroing the enforcer.
Open the door to Tayil N'Velex's cell at ( 11, -67, -7 ) Copy/waypoint 11, -67, -7 and speak to her.