A Coldharbour Keelhaul

Quick Walkthrough
# Talk to Devas Terano and learn about the Soul Anchor.
# Bring the Soul Anchor to Devas Terano.
# Be confronted by Noga-Togroi and get an order to kill Devas Terano and return the artifact back to the shrine.
# Search for Devas Terano.
# Talk to Devas Terano and either kill him, or spare his life and slay Noga-Togroi instead (see details).

Detailed Walkthrough
thumb|right| , a Daedric shrine to Molag Bal. This is where Devas Terano is sending you. 
Fetching the Soul Anchor
thumb|right|The   will be either a trident or saber. This is determined by the player's Long Blade and Spear skill levels. thumb|right|The guardian of the shrine has little love for thieves...
In Tel Ouada you can find a low-ranking House Telvanni member named Devas Terano in his house. Devas Terano will immediately try to recruit you to help him, saying that you look like "a seasoned ruin-dweller". He will then go on and tell you that he's a scholar of Daedric artifacts and is currently conducting a research on an item called the  . He tells you that the artifact is located in a nearby shrine of Baelkashpitu. If you mention that you don't think it's a good idea to steal from the Daedra, Devas Terano will dismiss it saying that in a shrine filled with treasures nobody will even notice the Soul Anchor missing.

Baelkashpitu is located relatively close, east southeast of Tel Ouada, but on the wrong side of the mountain. You can get to the shrine directly if you cross the river and either levitate or use your high Acrobatics to get to the other side. Alternatively, you can take a little detour and head south and go around the mountain. The shrine is inhabited by Daedric creatures and three hostile worshippers who will give you a tough fight unless you can sneak past them. The Soul Anchor will be lying on an altar at the foot of the statue of Molag Bal. The artifact will be either a saber or a trident.

Note that even if you've looted the shrine before the Soul Anchor will still be there, since it appears only after the quest has started.

Meet Noga-Togroi
When going near boat in Tel Ouada, the Noga-Togroi will teleport in front of you and order you to kill Devas Terano and return Soul Anchor to Baelkashpitu shrine in three days time.

First way of completing quest
Doing as Noga-Togroi told you.

To find Devas Terano go to his house and talk to Aligae about him. To get information you must have high disposition with her. She will tell you Devas Terano went to Bal Orya to sell Soul Anchor. Go there, he will be in inn, and get Soul Anchor from him, then kill him and return with weapon to Baelkashpitu.

Noga-Togroi will let you keep the Soul Anchor in reward.

Second way of completing quest
Wait three days to be teleported to Baelkashpitu and prepare for confrontation with Noga-Togroi, he will tell you failed and attack you.

After killing him go to Bal Orya to Devas Terano. He will tell you that he already sold Soul Anchor. You will get 500 gold pieces from him as a reward, and you can still kill him and loot 9000 gold pieces from his body. This way you wont be able to keep Soul Anchor, but you will be a rich man.

Third way of completing quest
Same as the first one, except that you not kill Devas Terano and still keep the artifact.

After disturbing conversation with the daedra near the boat in Tel Ouada, go back to Devas Terano house and speak with Aligae. With high enough disposition (you can intimidate her if you wish a little roleplay) she will tell you that her companion went to Bal Oyra to find potential buyers for the artifact. She will also beg you to not do any harm to Devas Terano.

Go to Bal Oyra inn. Devas Terano will be there on the first floor among other guests. Talk with him, he will be very scared of your story and just give you the Soul Anchor back right away. You can let him go home. Then, you can confront Noga-Togroi in Baelkashpitu. Either wait for three days to be teleported to the shrine automatically or just go there and do the job.
This is the best possible way of completing the quest, as you keep the powerful weapon, slay the evil daedra and don't have to kill poor dunmer in the process, doing as Aligae begged you to do, and sparing the lives of those two unlucky artifact smugglers.
 
Notes
You can find Devas Terano in his house in Tel Ouada after slaying Noga-Togroi if you choose third path.
If you visit Baelkashpitu before taking the quest, Noga-Togroi will be there and will be hostile. However it will be impossible to reach the monster as it will be under the shrine floor, so you can only approach daedroth if you use console cheat TCL. You can clearly hear the monster roaring if you walk around the daedric statue.

Bugs
 

Quest Stages