(mini-turn)
"How convenient! What is your business with this Sharn? I have recently joined this very guild, so I should definitely come meet her!"
Go meet Sharn with friendly Khajiit.
"A simple request for information. Although, is joining the guild so easy as to do it overnight? Taahni would be interested in a chance to hone her skills."
Go find Sharn.
The Dunmer woman behind the desk speaks up again before you walk away. "If you want to join the guild, come speak to me some time."
Sure enough, going down into the basement there's an Orc in the corner to the right, face buried in an open book. As you approach, Taahni introducing herself, the orc glances up. "No. No interruptions! How many times.... Oh. You are one of Caius' associates? That is a different matter." Sharn stands up and pushes her chair in. "Caius and I have a very satisfactory arrangement, and I'm sure we can come to some sort of agreement, if you will complete a little errand for me." When told this was expected, she elaborates.
"The errand, then, is very simple. I need the skull of Llevule Andrano. You'll find it in the Andrano Ancestral Tomb. That is south of Pelagiad, just off the road, just before you reach the fork where the road goes southwest towards Seyda Neen and southeast to Vivec. But take care not to upset the natives. The Dunmer have some peculiar primitive prejudices against necromancy, and take grave objection to unauthorized tomb visits. Also," she goes over to the shelf by her desk and opens a box. "You may need an enchanted blade. Some spirits are immune to normal weapons. Here. Take this old shortsword. And maybe these old scrolls will come in handy." She plonks the items on your side of the table and looks back at her book.