The third quest is activated when you enter the Lost City, beyond the Far Oasis, for the first time, once the sky darkens. It's necessary to complete as doing so also allows you to get one step closer to the Horadric Staff required to complete the second and sixth quests, and with them the Act.
|Ask Drognan about the strange darkness.|
If you talk to anyone but Drognan upon first returning to town:
|Claw Vipers! This outer darkness mirrors the inner blackness of their souls. It is they who have eclipsed the sun, I'll wager. They are a venomous band.||Two men arrived late last night bearing a story about evil magic. They said they saw a gathering of giant snake creatures performing some arcane ritual. They sound like the Serpent Men of the desert.|
|My astrologers failed to predict this eclipse. You should seek Drognan's advice.||Drognan may have some advice on this matter. Hmm... I think I'll speak with him myself.||This unnatural nightfall is no doubt caused by evil sorcery. Drognan might know what we are dealing with.||Drognan, the wizard, will have some idea as to what is happening.|
|This midday darkness reeks of foul magic! My men and I are trying to keep the peace, but this kind of thing really scares people.||This whole place is one big ale fog.||This permanent darkness is very unsettling. Hmmm... It would make navigation by stars easier for me, though.||The sun has grown disgusted with the terrible deeds it must shine upon each day. Damnation is upon us all.|
Talk to Drognan:
|I've been researching this lengthy eclipse and I believe it to be the work of Claw Vipers.|
Find their temple beneath the desert sands and you may find the source of this curse.
|Destroy the Serpent Altar in the Claw Viper Temple beneath the Valley of Snakes.|
The entrance to the Valley of Snakes is somewhere on the perimeter of the Lost City. If you explore, you can find a waypoint and a trap door down to the Ancient Tunnels, and you may encounter Dark Elder.
This is an optional area, randomly populated by three of the following four monster types: Embalmed, electric Horror Mages, Invaders and Plague Bearers (so there's 75% chance of being populated exclusively by undead). There's also a chest guarded by a non-random Unique monster, in addition to those randomly spawned.
Valley of Snakes
The Valley of Snakes is a small area, not populated except for a possible Fire Tower or two. The entrance to the Claw Viper Temple is in the middle of it.
Claw Viper Temple Level 1
The first level is randomly populated by three of the following six monsters: Claw Vipers (2), Salamanders (2), Embalmed, and Guardians with Bone Warriors (this means Claw Vipers and Salamanders can be picked twice, so each has 80% chance of spawning, while Embalmed and Guardians each have 'only' 50% chance of spawning; there's also 80% chance of being populated exclusively by Claw Vipers and Salamanders). There can also be Fire Towers and Mummy Sarcophagi, which can spawn Dried Corpses.
The most direct route to the second level is likely to be found by traveling left. Before going down the stairs, you may want to open a portal...
Claw Viper Temple Level 2
If you haven't asked Drognan about the strange darkness, you get a second prompt upon entering. Whether or not you ask him, if you return to town before completing this quest:
|I've discovered a reference to a similar eclipse several hundred years ago. It says that some desert-dwelling snake demons had erected an evil altar, which caused the sun to go black.
Perhaps we are dealing with something similar here. Look for an altar in the Claw Viper temple.
|The source of this spell is probably a magical altar. It will not be enough to kill the Claw Vipers. To reverse the spell you must destroy the altar.||The Claw Vipers practice evil magic. They have also been known to kidnap travelers and sacrifice them to their dark gods.|
|Well... I don't know much about the habits of Claw Vipers, to be honest. Drognan will probably know something about the nature of the magic at work.||The calculated coldness of the reptilian brain makes the Claw Vipers uncanny adversaries.|
|I was going to go to bed, but then I realized that I have no idea what time it is. It could be the crack of dawn, for all I know.||I usually charge for rooms by the night.
But I may have to soon change that.
|Don't worry! My men and I have an iron grip on this town. If those cursed Claw Vipers are plotting anything against us, we'll be prepared for 'em.|
|This eclipse is a definite manifestation of evil.||It's strange when the morning after the night before... is still the same night.||I've had about enough of this darkness. I don't even know what day it is anymore.|
The second level is similarly populated to the first (except there can be no Fire Towers or Mummy Sarcophagi), but it's considerably smaller. The layout is always the same: you enter on the northeast side, and the Tainted Sun Altar is on a large earthen platform in the middle of the room to the southwest. The only way to walk up to this altar is via stairs cut in the southwest side of the platform.
However, Fangskin spawns in the south of the room, and due to its speed and that of its minions it's unlikely you can run up the stairs to the altar without being intercepted, even if other monsters don't obstruct you. It's best to hug the wall and try to clear the north half of the room first, to give you more room to maneuver in this confined space: a charging Claw Viper or Salamander always hits and cannot be blocked, so things can get ugly if you get swarmed.
If you can make it up the stairs or Leap or Teleport up there then it makes things considerably easier: Claw Vipers and Salamanders are too large to follow, so ranged attackers or casters can kill them in relative safety, while melee attackers can use the stairs at a much-needed choke point. Of course, once you're up there you don't need to kill anything if you can escape back up to the first level, or cast a portal.
|Speak with the townsfolk in Lut Gholein.|
Deckard Cain only speaks the following if you talk to him first upon your return:
|I've been speaking with Lord Jerhyn, and I sense that he is becoming more and more agitated by something. You should try to talk to him again.|
If he still won't take you into his confidence, seek to prove yourself a bit more. I gather that his respect for you is growing.
Don't bother talking to Jerhyn (again) until you've talked to Drognan about the Arcane Sanctuary. Talking to Lysander and Meshif may remind you if you forgot to pick something up...
|Ahhh... Claw Vipers are fond of magical artifacts. Did you happen to find one in their temple?||So... Did you plunder any booty?|
|You did well in destroying the Claw Vipers. We are all glad to see the sun returned to its former glory.||Drognan seems to have taken you into his confidence. This is good, for you will benefit from his wisdom.||The sun again shines on Lut Gholein! I'm beginning to like you, traveler.||With renewed daylight, one may gather the wits that were scattered about like restrictive undergarments in the darkness.|
|You have done well to restore light to our world.||Ahh... It takes but one eye to revel in the beauty of our restored sun.||I'm glad that's over with!||So, this is daylight... It's over-rated.|
Talking to anyone completes this quest.