Oblivion:Turning a Blind Eye

Quick Walkthrough
# Wait until Methredhel finds you and gives you a message.
# Meet and talk to the Gray Fox at Helvius Cecia's home in Bruma.
# Travel to the Temple of the Ancestor Moths.
# Ask the monks about the Moth Priests.
# Find your way down through the catacombs.
# Retrieve the Stone and find your way back out.

Detailed Walkthrough
Fencing the Goods
In order to start this quest, you need to have fenced at least 600 gold in stolen goods. Once that's done, Methredhel will eventually arrive with a message for you to meet the Gray Fox at Helvius Cecia's house in Bruma. The fastest way for this to happen is to travel to the Imperial City and wait for 24 hours, at which point Methredhel will appear. Another option is to go to Methredhel which will initiate the dialogue about the message.
Head to Bruma and enter Helvius' house where you will finally meet the Gray Fox.

He'll ask you to steal Savilla's Stone from the underground catacombs connected to the Temple of the Ancestor Moths, a remote monastery for retired Blind Moth Priests, and marks the location on your map. He warns you not to shed innocent blood but says there will be no blood price on your head for the stone's guardians, human or inhuman. He also tells you to be well prepared as the area is extensive and well guarded. Bring lots of lockpicks or the Skeleton Key; alternatively, if your combat skills are better than your security, there is a common area on the right shortly past where Brother Holger leaves you. The guardians in there carry a crypt key which will let you through all the doors; just lure one out into the hallway (this is the point where the blood price ends).

Finding some Moth Priests
Travel to the monastery, far north of Cheydinhal (near Azura's Shrine if you've found it earlier), and speak with any of the servant monks to learn a bit about the Moth Priests. They don't know anything about the stone, however. Speak with Brother Holger (he may be inside the Ancestor Moth Crypt) about the stone and he'll lead you to the secret catacombs if his disposition is greater than 80. You'll need to do some disposition raising before anyone will tell you anything.

Follow the quest marker through the twisty maze full of monks and undead. The monks may be blind but they are not helpless and have good hearing. There's no blood price for killing them though and they have keys. There are several locked doors from "Average" to "Very Hard" in the catacombs. Watch out for traps on the third level. These include mace tripwires, a log tripwire, a gas chamber, floor spikes that hurt if you jump on them, and a few others.

Getting the Stone
There are two stones in the middle of the room. Savilla's Stone, i.e., the one you are trying to get, is off to one side of the central platform. In the middle of the platform, there is a Dark Welkynd Stone which will fire spells at you as you approach.

Keep an eye on the Dark Welkynd Stone at all times. This variety of Dark Welkynd Stone will fire at you even if you stop moving, so whenever the stone is glowing brightly, wait for it to fire and then sidestep to avoid its blasts. Invisibility and chameleon do not prevent the stone from detecting you.

There are various methods for getting the stone.
You can kill the Blind Moth Prelate (without any blood price) if you want.
You can sneak behind the prelate. Although he is blind, he is able to detect you unless you have good sneak skill. When you are standing behind him, you will be spotted by the Dark Welkynd Stone, but since you are behind the prelate, the blasts from the stone will only damage him. He will try to heal himself, but eventually he dies.
With high enough sneak skill and/or Invisibility, you can sneak past the prelate and grab the stone without him noticing.
You can shoot the stone off its altar with a fire spell (shock or frost spells do not cause much impact upon hit). With careful positioning, it is possible to move the stone to a location where you can grab it without being noticed by the prelate.
You can use a long range Telekinesis spell and pull it to you (the range needs to be longer than the 10 feet provided by Remote Manipulation).
You can quickly run down the stairs, grab Savilla's Stone and hurry back out. If timed correctly, it is possible to avoid the blasts from the Dark Welkynd Stone and evade the prelate.

Finding Your way Out Again
Instead of taking the long way out of the dungeon, you can just turn right from where you took the Stone and find a ladder to the Monastery. Before you leave there is a chest near the bed on top of which there's a handbill entitled Instructions: The Gray Cowl describing a "quest" the monks would do: discover the origins of the Gray Cowl of Nocturnal. Later on, ask the Gray Fox about this new topic and listen to what he has to say.

Blood Price
Killing any of the following NPCs while this quest is active will require you to pay a blood price to Armand:
Brother Hjar
Brother Holger
Brother Hridi

Notes
Brother Holger's voice completely changes in tone and accent for the ''"Okay, okay, I'll show you..."'' line, similar to a beggar's voice, before returning to its previous tone immediately after.
If you are level four or higher, the Blind Moth Prelate guarding Savilla's Stone always has a high level amulet or ring which is randomly generated when you enter the final zone (i.e., when you pass through the door that has a load screen) on future visits to the temple (when he respawns). See the temple's notes for details.
  When doing this quest on console, this ring/amulet is set when you get the quest from Methredhel (or at least prior to meeting with the Gray Fox). However once the Temple respawns outside of the quest line, the ring/amulet is randomly generated when you enter the last zone as described above.

Bugs
 
The most serious possible bug is during the final cutscene of The Ultimate Heist. To avoid it, you must be careful about the order in which you do the Thieves Guild quests.
If you try to simultaneously do the quest Taking Care of Lex quest (which is supposed to precede this quest), the Stranger cannot be found in Anvil's Abandoned House. You will need to complete Turning a Blind Eye, at which point the Stranger will reappear in Anvil.
 
This may be fixed by opening the Console and typing in  . This will place you at the next stage with a message telling you that the Gray Fox will be contacting you soon.
Another way to fix the bug is to use the console command   . This will place Amusei directly in front of you. If "Turning a Blind Eye" is in your completed quest menu, Amusei should then tell you that the Gray Fox has a message for you.
 
 Entering   into the console will allow the note to be removed.
 

Journal Entries