Reskin will tell you part of his Tavern was taken over by a new owner and he doesn't like it.
He will tell you the secret passage is between the two barrels. Once you've passed through the barrels,
you will need to kill the guards and Asturin(level 7) go to the back down the hold into the Theives area
Once there you will face (level 9)Theives and (level 10)Assassins, You must pass through the room with 2 assassins in it.
Then go to the middle room in that hallway, Kill the theif master. Map coming soon. Don't forget to get the key from his body
and grab the chest in that room and in the room to the right(right by where the assassins were that you just killed).
Then return to reskin and wait until he rewards you with experience and a recipe to make a stat pot.
For other recipes please check out the Alchemy page