Contract: Phantom of Eldberg - Skellige
Quest Giver: Mulbrydale Notice Board
Other Requirements: N/A
There are many different ways for you to accept this quest. During The King Is Dead - Long Live The King Quest if you choose to fight Madman Lugos in a fist fight he'll comment about this quest, placing it in your journal. Or you can use the Arinbjorn's Notice Board/speak with Jorund directly in the Arinbjorn Tavern (pictured above). Last but not least if you investigate the area this quest takes place you'll receive the quest then.
Assuming you picked up this quest from the Notice Board or during The King is Dead quest, the first thing you will need to do is speak with Jorund who is at the Arinbjorn tavern. Speaking to him will update your quest and send you to a lighthouse keeper up north.
When you arrive at the house within the quest marker knock on the door for a conversation with Mikkjal, the lighthouse keeper. Your dialogue with him will change depending on whether or not you've spoken to Jorund first - either way you'll receive the lighthouse key which you'll use for entry into the lighthouse. On the second floor of the lighthouse you'll find a letter on a bookshelf which will update your quest and have you return to Mikkjal.
Note: We won't be returning to the lighthouse for the rest of this quest and once you leave/complete this quest the door will be locked again; not allowing you entry. Loot everything inside now while we're still here and have access to the lighthouse.
For the next part of this quest you'll need to escort Mikkjal to the lighthouse and have him light the fire there - which is the only way you can defeat the monster, which is a Penitent.
The fight will be pretty straight forward, the same as fighting most other Wraith enemies in the game. Penitent will summon regular Wraiths which you'll have to get rid of while also dodging its attacks. Don't bother trying to hurt the Penitent enemy until Geralt comments about the fire being lit, he'll be invulnerable to your attacks until that happens.
Penitent Weaknesses: Moon Dust, Specter Oil, Yrden, Quen
Tip: If you are playing on an easier difficulty dragging out the fight so you can farm the Wraith's for the Mutagens is a pretty good idea.
Upon defeating the Penitent, if you found the letter on the second floor of the light house you'll be given the choice of either letting Mikkjal's mistake slide or tell him to leave. The choice is yours and doesn't alter the rest of the quest. Return to Arinbjorn and speak to Jorund in the tavern. Note: If you didn't investigate the Notice Board to initiate this quest then do so now, for the next scene.
Inside of the tavern Jorund will be harassed by Kori and Kraki, you met these two earlier in the quest if you first picked up this quest by visting the Notice Board or Jorund in Arinbjorn. If not it's your first time meeting these two. After a little bit of dialogue things turn violent and all three people will end up dead.
Note: If you completed or failed the quest King's Gambit prior to now then you will not get this scene and the quests Stranger in a Strange Land as well as The Cave of Dreams and Unpaid Debt will all be unavaialble for you.
After witnessing the scene you'll automatically be given the quest Stranger in a Strange Land. The next thing that happens is unavoidable, the moment you leave the tavern you'll be thrown into some dialogue after which you'll be put into jail. This quest is officially completed but you'll have to do Stranger in a Strange Land now before you're able to be a free man again.