Here's a potion. And Joe will be at this tavern. It's his favorite tavern. He'll stay here. You'll drug him with a sleeping potion and take him to the Dungeon. He gives you a map. There, you need to activate the lever, and the entrance will be blocked. Joe will stay in the dungeon. Here's an advance payment - 225 copper coins. You'll get the rest later.
Then I turn to the bartender: "Bartender! Two more mugs for me!"