Vaermina (Quest)

The wizard Arkved has taken Vaermina's Orb. After offering a Black Soul Gem, she asks the Hero retrieve it.

Arkved's Tower
Vaermina asks the Hero to fetch Vaermina's Orb from Arkved, located in his tower, south-southwest of the shrine. There is an option of two entrances. If standing at the door to the tower face North, walk straight a few feet and they will discover underneath some shrubs a trap door leading directly to the room containing the Orb.

After entering Arkved's Tower, start fighting the way through leveled daedra. In one of the rooms, there is a table set with food, cutlery and plates. However, after traversing the second corridor, they will enter a seemingly empty room apart from the daedra. However, looking up, they'll see an identical table on the ceiling. A lot of these odd features populate this dungeon.

Next area is Arkved's Void. Nothing worthy of note here, except don't fall off the bridges or islands and there are no enemies to worry about. There are a couple of chest on the different islands with minor loot.

Follow the marker and enter the door into Arkved's Lost Halls. Try and face the daedra one at a time, as even at a higher level they are difficult to defeat. Find the way through the numerous corridors until they find the door to Arkved's Hall of Changes. Don't enter the door to Arkved's Oasis, there's no point, as there's no loot and even more daedra.

Be careful in the Hall of Changes, as there are several powerful Dark Welkynd Stones along with numerous daedra. Follow the compass and map until they come to Arkved's Rending Halls. This section is even more heavily guarded than the last, so be on guard at all times. Once they reach the end, enter the door to the final level, Arkved's Death Quarters.

Arkved's Death Quarters
Inside, one will find Arkved himself, but he's lying on the bed, unconscious. Grab Vaermina's Orb and if feeling like it, read the Handwritten Note near it, which sheds some light on the nature of the orb.

Shrine of Vaermina
Get out through the door at the back and get back to the shrine. Return the orb to Vaermina, and he will present the Hero with the unique staff called the Skull of Corruption.

Trivia

 * One can't pickpocket Arkved, but one can kill him and loot the corpse for his White Mage's clothes and a small sum of Gold; this will not affect the quest and does not appear to count as a murder crime.