Hi! I'm stuck with the final part of quest, do I have to fight the four sisters? How can I advance this quest?
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As the dialogs suggest, it's not the goal to defeat them in battle. A while after the start of the battle, dalogs and choices will pop up. If you make the right choices, you'll be able to find a peaceful solution to the encounter.
If you defeat the goats, or make a wrong choice and no more dialogs pop up, you have to leave and re-enter the area to be able to restart the battle.