Keldorn's Companion Quest - Baldur's Gate 2
Keldorn is a Lawful Good Human Inquisitor that you can recruit as a companion. You can find Keldorn in the Temple District Sewers during the Investigate and Destroy the Cult of the Eyeless side quest. When you enter the Government District for the first time with Keldorn in your party he'll initiate dialogue with you and ask to visit his family. This begins the Keldorn Wishes to Visit His Wife and Family quest.
Note: Much like many of the other Companion Quests in this game if you wait too long after starting this quest Keldorn will begin to complain before eventually leaving your party and returning home himself. If he leaves your party you can find him again at the Firecam Estate.
The Firecam Estate in the Government District is Keldorn's home and the building you'll need to visit to advance this quest forward. When you enter the building there will be a short scene between Keldorn and his wife after which he will ask you for some advice. Depending on what you say to him this will drastically change the outcome of the quest.
At this point in time you have 2 options, you can recommend Keldorn confront William or allow Keldorn to hang William and imprison his wife. If you support Keldorn's decision to hang William and imprison his wife then you can find him a day later at the Radiant Heart building in the Temple District. He will be available for recruitment again at this time and you'll receive no EXP reward.
Encouraging Keldorn to confront William is the best option for this quest, despite it being a terrible idea if this were real life (though I guess the other option is a terrible idea too). You can find William in the Mithrest Inn located in the northern portion of Waukeen's Promenade. Mithrest Inn will be marked on your map.
William and Keldorn will have a brief discussion after which Keldorn will calm down and be more reasonable. Return to the Firecam Estate and speak with Lady Maria again to get to our final fork in the road for this quest. Keldorn will ask to spend some time with his family and you will be given 3 different options...
1. You can release Keldorn from your service entirely which means he will be no longer available to you as a companion until Throne of Bhaal.
2. Encourage Keldorn to take a single day off to spend with his family. After 24hrs passes you can find Keldorn at the Firecam Estate where you can recruit him again.
3. Tell Keldorn you ain't got time for any of that family nonsense and that he needs to stay with you.
Regardless of the decision you make during this part of the quest you will be rewarded with 15.5k EXP and the quest will be completed.