The Rot in the Slums is a quest in the new Paris DLC of Assassin’s Creed Valhalla.
Your objective is to find and eliminate Bishop Engelwin.
Here’s a walkthrough of The Rot in the Slums in AC Valhalla.
To begin the quest, head to the slums of Paris as marked in the map below.
Find and speak to Sigfred
Once you’ve reached the slums, look for Sigfred. You’ll find a path to the sewers near a flag.
Go down and you’ll see some rats. This part is very similar to the game A Plague Tale where you need to fend off rats.
Just swing your weapon to shoo rats away but you can’t kill them.
Walk inside and you’ll see Sigfred.
Find and assassinate Engelwin
Before you can find Engelwin, you need to get clues. Head to the location marked on the map.
Inside the tavern, look around for clues. There may be a note on the table.
Then, talk to the man nearby for another clue. You should be given two separate clues but you only need to find one.
I chose to help the drunk’s daughter who is in the Flooded Slums. The location is shown in the map below.
You’ll find a girl surrounded by soldiers. Take out the soldiers first and then untie her.
She will lead you to the door that goes to the sewers.
Go down the sewers and you’ll reach a locked door.
Look towards the left instead.
You’ll find a way to descend even lower. Once you’re down, follow the path until the dead end and you will need to climb back up. You’ll find yourself past the locked door.
Continue forward and eliminate the bandits along the way.
Finally, you’ll find the key and a note.
Next, head to the church as shown in the map.
Use the key to the northern gate and you can sneak in quietly.
You can enter the church from the top balcony. The balcony is just above the guy who has a key.
Climb up and talk to the man with a chat bubble.
You’ll then unlock an Assassination Event, which is a special type of assassination cutscene if you choose to do it later.
Loot the chest near the guy to get the special robe.
Go to your inventory and equip the Bellatores Robe.
Now, go to the ground floor and you’ll see a path downwards. Go down and you’ll be allowed to enter the area if you’ve worn the robe.
At the next part, use Odin’s sight and you’ll see two pots that can be lit up.
Equip your torch and light them both up.
Finally, you’ll reach the area where Engelwin is. Here, you can choose to get the special assassination or you can just assassinate him normally / defeat him in battle.
After killing him, leave the sanctum.