Niall got some letter that says he won a prize and to come to Mugsburrow to retrieve it. However, being old and all is preventing him from going to get the prize, so he asks you to go in his stead. If you don’t know where Mugsburrow is, it’s located on the southern end of the Drylands and requires the airship to get to it. It’s pretty much straight south from the Wallowing Hole. Enter Mugsburrow and you’ll find a chest in the middle room (3 Inferno Crystal Clusters), so grab the contents and continue to the southern room. When you enter, some bandits will show up, so fight them off (they’re level 55) and return to Niall in Evermore to finish off the quest.