Quest giver: Mirabelle
Experience: 6000
Gold: 10000
RC: 20
Meet Mirabell by night
Meet Aelinore by night
Escape the dungeon
Before attempting this quest, you should have a few skeleton keys in your possession. After meeting the Duke for the first time, you'll find Aelinore in the demesne's garden. Approach her to trigger a scene. Keep talking to her until she asks for the jester hat Feste gave you. Doing this will increase her affinity towards you. Once done, leave the demesne and return to find Mirabelle in the castle's entrance. Talk to her to start the quest.
Return to the demesne by night and head to the garden left of the castle. You're not to be seen by anybody or else you'll be thrown in the dungeon. Speak with Mirabelle and she'll ask you to sneak inside and speak to Aelinore.
Enter the castle and carefully head to the throne room. Before moving, observe the fixed patterns the guards are following. You can stay in the shadows and avoid their line of sight to remain sneak past them. Go upstairs past the throne and enter the first set of stairs to the left then enter the doorway. Go upstairs again and follow the walkway to reach the tower where Aelinore is located. Enter it to trigger a cutscene.
After the scene, you'll be given two options:
1. Reveal yourself and stop the duke from his madness.
2. Stay hidden and let the duke finish.
(Selecting this option will fail the quest and will permanently remove Aelinore from the story, locking out further quests involving her)
After the scene, you'll be thrown in the dungeons. If you chose the first option, you'll be given two skeleton keys. If not, you should still have some in your inventory, as you're advised to bring a few at the start of this walkthrough. After opening your prison cell, you may find Ansell here (part of the the quest An Innocent Man) Otherwise, open the adjacent cell where you've been held and enter the sewers.
There's a lot of snakes, rats and spiders inside so just run away and ignore them until you reach the exit. From here, you should be able to wear your old equipment back.