The Wartales A Strange Smell quest is discovered once you reach the town of Marheim in the Vertruse Province and speak to the Mayoress in the Town Hall. She complains about a stench that has become a problem for the locals and asks you to deal with it. That's easier said than done, because you need to find where the smell is coming from.
Thankfully, the solution isn't too tricky, but you will need a thief in your group, some lockpicks, and a torch. As none of these items is too hard to get hold of, you shouldn't have much trouble coming to Marheim's aid. So without further ado, here's how to complete the A Strange Smell quest in Wartales, and how to craft the items needed to complete it.
How to complete A Strange Smell in Wartales
After you've arrived in Marheim and spoken to the Mayoress at the Town Hall, head to the Thousand Steps Market and look for a locked trapdoor on the ground. This trapdoor might not be in the same position for you, so have a look around the entire floor of the market to find it.
The trapdoor needs a lockpick to open; you can craft these at your camp with your tinkerer. You'll need some iron ore to craft them with, and while you're here, it's a good idea to craft a torch, ready for later on in the quest too.
Head back to the market in Marheim and have your thief use the lockpicks on the trapdoor. Once inside, you'll find rats guarding their nest. Choose to fight, which will throw you into battle with a big group of them, though you can use rockslides to help pick off some if you're careful with your positioning. Once they've been taken care of, it's time to sort out the nest.
Interact with the nest blocking the waterway, and you'll have the option to burn it using a torch. You can now return to the Mayoress in the Town Hall to claim your reward. Smell sorted!