Once you get to Severed Hand, you'll see a scripted event outside the Building. Go inside and you'll find that the Severed Hand isn't right. As it goes, Larrel found out that a huge army was invading, and he cast a very large spell that didn't go right, and turned everyone in the Severed Hand into Undead or Shadowed them, Driving them insane. Some of them are still ok, but still kind of crazed. you must find the 4 pieces of the Machinery to finish the Severed Hand, and undo the spell that was cast and stop the spell and allow Larrel to speak with you and use the Heartstone Gem to find the source of Evil..

Severed Hand Area Zero

The first floor is full of Shadowed Orc's, Skeletons (Bladed on the Eastern Site) along with lots of shadowed Goblins in the north part of the map. On the east part (Accessible from the stairs from the 2nd floor) you will see Bladed Skeletons as I stated, and 3 sets of 4 Shattered Souls (Pretty tough) you will need to run right up to them and stop them from casting their spells.

Also in the eastern area is one of the 4 pieces of Machinery you'll need to finish Severed Hand.

The second floor has many more monsters, including Worgs, Orc's, Skeletons and Shaman. And more Shattered Souls and Skeleton Warriors. Find the Shadowed Goblin Trainer, and get the Bag of Holding (Kill him). Its a nice item to own... Also, there are Shadowed Orc Marksmen, get them out of the way quick, because they can really inflict damage..

Once the second floor is cleaned out, head up to the 3rd floor and get ready for some more 'fun' <g>

This floor has even MORE monsters, and some really awesome items to be had. Start off by cleaning out the south part of the map, you'll encounter a few burning skeletons - when they die, they explode, so try to kill them with melee attacks. Also, you'll find many Armored Skeletons and tons of Bladed Skeletons in the east.

Again, you'll run into more "Shadowed" monsters.. boring.. anyway, kill them and go get a powerful item known as Misery's Herald, its a cool item. See Map Above for location

Have your thief set to detect traps, there are a few in the area, Also see map for red lines, indicating traps. Finally, when you're done, head up to the final 'floor' with the 4 tower entry points!

Tower Names

This map has 4 tower entry points only 3 of them are important, each of the 3 is kind of tough, and each one has up to 5 levels. You'll find lots of good items within these towers!

The Sheverash Tower
Kaylessa asks you to dispose of her Warriors that have all become insane or crazed. She says they have been dead for a long time, and now its just evil that keeps their souls from moving on. This will be a slightly hard battles, but once you finish with the tower, go meet Kaylessa again to tell her that you have succeeded in her wishes. She will tell you that she is the only one left to die, so she asks you to kill her for the Astrolab Machinery Piece. Do it. (Also a few items to take).
Now on to the next tower.....

Solonar Towers
A non-combatant Cleric will ask you to also put her fellow Cleric's to rest, they are all upstairs, so here we go again, head up and be ready for some tough battles that include magic.. She will ask you for some holy water, so she can cleanse her pools.. You can find the Barrel of Holy water on one of the Towers. Also, another part of the Astrolab can be found on the second floor of this tower!

Corolan Tower
This tower is where many of the battle plans are readied. The Astrolab piece is also on the 3rd floor of this tower. 
You will meet yet another person, this time a female mage.. She asks you to find her some seeds do that she can restore her gardens to their once grandness. You can find the seeds in Dorn's Deep.

Remember to take a few of the books from the Library to take back to the Wizard in Kuldahar for Experience points and a Magical Item (Warning, without the patched version, the item to be given to you may not be transferred, and you'll see the words "Cannot find script")

After you found all the Astrolab Pieces, you will now need go to the Sheverash tower, and up to the Machinery room and speak with the Mage by the machine, he will except the machinery parts happily and this will allow Larrel to remain sane enough to use the Heartstone Gem, and find out what the source of the Evil is. It's Dorn's Deep.. Now to Chapter 4!

Labelas Tower
This tower is the one that is pretty much bare. Its just a tower to enjoy the scenery. <g>

Holy Water Location on Map