Online:Our Poor Town

Quick Walkthrough
# Talk to Stormy-Eyes.
# Find Stormy-Eyes' key and collect torchbug wings.
# Talk to Asmalah the Caller.
# Return to Stormy-Eyes.

Detailed Walkthrough
Upon entering Darkwater Crossing, you'll find the entire town destroyed by trolls, with several dead bodies about. The survivors can be found in a cave at the southeast edge of town. Go in and find Stormy-Eyes praying over an altar, where another Argonian is laying injured. 
:"Too much to do and too little time."
:Is there anything I can do to help?
:"A stranger offers aid? You dare to put your own life in danger for the benefit of others? That sounds too good to be true."
:I just want to help.
:"Well, I would be foolish to turn down help, wherever it comes from. I need certain materials to perform the ritual. Can you gather them for me?"
:What do you need?
:"I need you to catch torchbugs. I need five pairs of wings. No more, no less. I also need the satchel from my home—the intact building, the one with the sturdy lock. The key should be in an urn near the house. I tossed it in there when I ran by."

The   can be obtained from torchbugs in the area, marked by quest icons. Harvest them as you normally would. The   is found in an urn just outside of the cave, to the north (not his house, as he says). It is marked with a quest marker as well. Be aware that there are several other containers around the town with quest markers as well, which will only drop useless quest items. You have the option of searching Logangar Brittleblade's corpse during the quest. He's face-down in a camp south of Stormy-Eyes's house.

Stormy-Eyes' house is the only intact house in Darkwater Crossing. When you enter, you'll see a Redguard wizard searching through a bookshelf in the corner. Confront Asmalah the Caller, and he'll try to make feeble excuses before he leaves. Follow him out. He'll instruct two warriors named Adruzan and Durdira to slow you down, but follow him regardless to the edge of town. Once you take him down to 50% health, he'll spawn a portal and go to the other side of the river. Follow him, where he will be out of excuses and he will explain himself.
:"How dare you help the Argonians. The filthy lizards! They killed my wife! She put her faith in the Dreamwalker. Put her life in his hands …."
:What do you mean?
:"My wife was ill. This Dreamwalker. He promised he could cure her. By entering her dreams. She swore off practical medicines. Said there were other ways. They were lies! I held her hand as her life slipped away. He killed her."
:'''The Dreamwalker did? Is that why you're here?
:"I came here to make them suffer. All of them. To make them feel the pain as I did. I put blood around the village. Lured the trolls here. I watched them destroy the place. And now, it seems, I hold the life of another in my hands."
:What life do you speak of?
:"Whoever the Dreamwalker is trying to save. He sent you for his reagents, didn't he? That's why you were in the house. That's why I was there too. To make sure he never stepped into another dream again. Let me go and I'll tell you where to find them."
:Are you trying to bargain your life for another?
:"I tried to destroy this monster after what he did to my wife. But it's out of my hands now. Let me go and I'll tell you where I hid the reagents. Kill me and you'll never find them."
:: 
:::"I put the reagents into a vase and threw it into the ruined building I ran by. Take them and get back to your Dreamwalker. Just know it won't work. She's dead, regardless of what you do. Just … just like my wife."
:: 
:::"Then I die. And the Dreamwalker's reagents are lost for all time. Do it! Take my life! My wife … she waits for me …"''

You can either kill him or promise to let him go. If you kill him, you will not find Stormy-Eyes's reagents, the ritual will fail, and Sister-of-Wind will die. If you spare him, he'll tell you where the reagents are located. Go back to town and collect the   from an urn in the ruined house, which lies east of the cliff Asmalah teleported to. Once you have everything the Dreamwalker needs, bring them to Stormy-Eyes. He will take them, perform the ritual to cure Sister-of-Wind, and then give you your reward.

Notes
Be aware that the cave is underneath the Dragon's Hallow World Boss site. Some quest markers may look like they lead into the worlds boss, but they are actually pointing underground and can only be accessed through the cave.
Stormy-Eyes' house is actually unlocked from the start of the quest and you can enter at any time, but you cannot continue the quest without the key. Picking up the key is the trigger to spawn Asmalah. 
 

Quest Stages