Grimgnaw's Tale - NWN Henchman Quest (Chapter 3)
Grimgnaw's Tale is the third and final quest that's given to you by Grimgnaw, one of the available Henchman in the Neverwinter Nights Main Campaign. Every Henchman will have a unique quest that will become available from talking to them during the chapter. These quests are locked behind character levels, if your Henchman tells you that they will "finish the story later" it means you have to level up more.
Note: If you did not complete this Henchman's quest during Chapter 1 and Chapter 2 then it will not be available to you during Chapter 3. Also, if you did not keep their quest reward with you from Chapter 1 and 2 then they will be unable to upgrade it and may not offer you the quest either.
For this version of Grimgnaw's Tale you're tasked with retrieving a Dagger that's found in the southeastern portion of the Coldwood Map. The Dagger can be found inside of a container at small camp which is tucked away in the corner surrounded by mountains. At this camp you'll also find an orc named Vaath who is part of the Save The Supply Lines quest.
As far as which Coldwood map you can find this Dagger on, it's the very first one that's just north of Beorunna's Well. If you need help locating this Dagger use my screenshot below - I have the map fully explored and open in the picture which should make it easy to locate this spot. Once you have obtained this Dagger all that's left is to hand it to Grimgnaw to complete this quest.