Did we miss anything on a quest? Is there something we didn't discover? Let us know!
1. This mission is not as straightforward as the first two, but the parts aren't difficult when taken one at a time. You're going to have to talk to three informants in Vivec about the same thing you've been investigating, the two cults. You can do them in any order, but we'll start with Addhiranirr first, located in the St. Olms Canalworks.
2. Take the Silt Strider or the Mage's Guild teleporter to Vivec, go inside the St. Olms Waistworks and from there you'll find some doors to the Canalworks. Be careful when you're in the Canalworks… there's a level 19 Fighter stationed near a door down there. If you get too close, she may go aggressive on you and if you're too low a level and don't have a TON of healing potions, she'll be very tough to beat. For an easy death at this point (if you've been sticking to the quest), try the Fighter and/or the door.
3. Addhiranirr is standing on the very end of one of the canal ways and since there's only two main canals down there, check both to find her. Like before, she'll want you to do something before giving up her info. If you get rid of the Census and Excise agent in the St. Olms Waistworks directly above, named Platorius, she'll talk to you.
4. Just talk Platorius into leaving town, or not in which case you'll need to raise Add's disposition to you next time you meet her, and she'll spill like a busted water main.
5. Next, head to the Foreign Quarter Waistworks and visit the Black Shalk Cornerclub. You're looking for the Argonian Huleeya. While he'll talk to you freely, he needs your assistance to escort him to a more suitable and private place. Take him across the way to Jobasha's Rare Book store, on the same level, and he'll inform you of what you need to know.
6. Finally, sashay over to the Temple District to the Hall of Wisdom to speak with Mehra Milo. If you speak with the patrons there, you'll find she's either in the Temple Library or her room. Try the Library first, and talk to her. Escort her to the back where she'll tell you about the Nerevarine Cult Dissident Priests and mention a book called "Progress of Truth" that you'll want to bring back to Cosades. You can find it either here in the library in the section as you walk in, or on Jobasha's Rare Book store. If you take it from the library, watch so that the Ordinator guards are looking the other way before you grab it.
7. Before you're through with her, she'll also inform you that she is likely being watched by the Ordinators, and to tell Cosades that should there be trouble, she'll leave a message with the codeword "amaya."
8. Now that you're finished with the informants in Vivec, return with the book to Caius and along with a promotion, he'll advise you to take some time off while he thinks over the info. After a day's time, talk to Caius for the next mission.