Docks

I will make this short and tell you what you need to do without any additions. First, kill as many thieves in the area as you can and collect smuggler's coins, then go to the "locked house" and kill all of the bloodsailors and get the tavern key (note that there are two entrances in this house where one leads to a dire bloated spider and other leades to bloodsailors). Next go to the tavern where you will be attacked by some hirelings which carry a note that you can give to Fenthik. To go inside the tavern you can either bribe your way in by offering five smuggler coins or get some bloodsailor clothes at the ship/boat. Using smuggler coins you can buy magical equipment from the merchant to the left of the tavern entrance. In the tavern you can bride or persuade your way to the lower levels. When you make your way to the woman prisoner, talk to her nicely and she will give you a locket that will grant you entrance to Silversails Trading Company (I believe it's the correct name of the building). Through there you go to Aqueducts and from there you take the boat downstream. Also in the Aqueducts there is a tomb of Never marked as "exit" on the map. After taking the boat downstream and following the road, you will eventually come across Callik and Vengaul. They are about to fight but Vengaul will say that you're there to help him and Callik and his guards will attack you.

Enemies to beware in the district:
Bloodsailor Lieutenants. These guys can hit hard and there are a variety of them. Some are mages others are fighters or monks. They can take quite a beating but thankfully they're almost always alone so you can concentrate on knocking him down or cast some sort of disabling spell.

Bloated Dire Spiders. There are some of these buggers in some houses but they are not that hard to kill as your first one are they? Just watch out for poison because it can quickly make you a loser instead of a winner. I suggest the same tactic, run around with a ranged weapon and shoot them. Spells do better of course.

Boss - Callik. He is pretty easy if you're a fighter and if you're not, then just shower him with direct damage spells and he'll be dead before you know it. The guards are simply pathetic. Sometimes Callik attempts a knockdown hit so be careful. Some people find this fight quite hard but I never had any trouble with it. Callik might even try to disarm but it happens so rarely and usually dies before he can use it.

After defeating him, talk to Vengaul and here you can make your own choice whether let him go or not. He doesn't want to fight you and will give the feather reagent willingly (it's in the glowing box). The amulet you got from Callik's body can be returned to the proper owner (Masterson) who is waiting in the Docks district. He is just a little bit to the northwest of the entrance to the Docks. I haven't mentioned an alternative entrance to Callik so I'll do so now. You have to have an item called "orders from Callik". It's a note left by one of the guards who were questioning the woman prisoner. The alternative entrance is to the west of the tavern. It's an easy to spot building because it's marked on the map. A mansion for the Moonstone Mask quest is also near it. The sundial house can be found northeast of the entrance. And that about sums up the Docks district and now we have all four reagents for the cure so let's return to Aribeth.

Hooray for the hero of Neverwinter! You brought back all of the reagents for the cure and you can now witness its creation as a reward. You might think that it will all be over soon but it won't. Before you agree to witness the creation of the cure, make sure you have no loose quests and that you have completed every quest you wanted because you won't be able to come back. Ever. In the cure creation room Oleff welcomes you and tells you to speak with people in the room. You can learn that Fenthik has talked Lord Nasher to give Desther keys to the palace or something and that the palace is unprotected from magic. That sounds very suspicious if you ask me. After talking to all people (Aribeth, Fenthik, Desther, Nasher), the cure will be created. Once the cure is complete Desther will grab it and flee leaving you with False Helmites to deal with. Fenthik goes after Desther and it looks like he's helping Desther. And now it's up to you to get the cure back from the hands of that arrogant cleric.