The Understone DLC introduces a new section to Bowerstone Industrial. The quest The Voice can be started in one of the factories near the entrance to Mourningwood. The location itself contains seven new houses and three new shops to buy/rent. You will fight a large number of undead Hobbes and undead wolves, summoned by old machinery. Your goal is to find the source of the voice heard in the factory back in Industrial. The path will lead you to an underground village that has existed for generations, under the premise that nothing exists on the surface, so they cannot leave. At the end of the quest, you are given the chance to tell the people they can leave, or not, and use them to earn you gold as slave labour.