Head over and speak with Erlina who informs you Howe is inside so you need to be careful. Go left and loot the two Elfroot then when the Guard notices you and summons soldiers from the rear, kill them. Turn the corner to find another Elfroot and enter the courtyard. Check out the two Elfroots , Deathroot , and the sack here then Erlina will stop you. You can simply kill the guards and have to battle your way through this part of the quest or place your disguises on and go stealthy, which is how the guide will go.

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You can just choose to charge into the estate or sneak in. Erlina can distract the guards when you get close.