Peace Disturbed - Skellige
Location: South of Kaer Trolde Harbor
Quest Giver: Skelliger (Old Woman)
Other Requirements: N/A
There are two ways for you to start this quest, the easiest and intended method is to speak with the old lady outside of the tomb on the southern trail leading here (pictured above and below). Alternatively you could stumble into the hidden entrance/exit to this tomb and make your way inside of it through that route. If you do, you'll receive this quest upon discovering the Nightwraith in the tomb.
While in the tomb you'll want to use your Witcher Senses and thoroughly search everything. There will be a body in here with a Relic quality sword on it as well as many crates and barrels that you can loot for alcohol which is useful for Alchemy, amongst other things.
As aforementioned in this tomb you'll find a Nightwraith, you'll have to use Yrden in order to damage it - as with all other night/noon wraiths throughout the game. On the bottom floor of the tomb you'll find some rocks which you can Aard away, clearing a path to the secret entrance/exit to this tomb. There will be two chests to find along this path if you would like to check it out, neither contain anything unique.
To complete this quest turn it in to the old lady that's pictured at the top of this page. If you're having trouble finding where this quest takes place, use my screen shot below for further guidance.