La Cage au Fou is part of the main story quest of Blood and Wine and is where you finally get to know that The Beast of Toussaint is none other than Dettlaff.
Tracking down a higher vampire is not going to be easy. You will need to craft a special concoction called Resonance to find where Dettlaff is hiding. However, finding the right ingredients is going to prove a challenge.
You will need to kill a Spotted Wight, a unique and powerful variant of a Wight that nearly drove the Witchers to extinction in the lore. There is also going to be an optional objective to get the Tesham Mutna armor set, a special heavy armor exclusive to Blood and Wine.
The following guide will tell you more about how to complete La Cage au Fou in The Witcher 3: Wild Hunt.
How to start the quest
The quest will begin right after you complete Blood Run. Regis will ask you to find him at his hideout in Mère-Lachaiselongue Cemetery which lies east of the Beauclair Harbor and north of Francollarts. You can also take a walk from the Belgaard Vineyard to reach the cemetery.
Something important to note is that La Cage au Fou has several objectives with sevearl different rewards. It is highly recommended to complete all of these objectives on your first visit to save time. You are also recommended to complete this quest before hitting level 43 or else your rewards will decrease in level.
La Cage au Fou walkthrough
When you reach the cemetery, the first thing you need to do is clear out all of the enemies over there. The only door to the crypt here is going to be locked, so you will need to find another way to enter Regis’ hideout.
Explore the cemetery a bit more to discover an open tomb. Drop down the hole and you will reach a fork where you can either go left or right. Both lead to the crypt.
If you take the left path
Going down the left path will meet a dead end. However, this is only an illusion. If you have The Eye of Nehaleni, you can remove the illusionary wall to loot the Casus Foederis silver sword from a sarcophagus.
Notice the left path in the room. Take that to enter the crypt.
If you take the right path
Going down the right path will meet some debris in your path that can be removed by using Aard. Continue on and you will enter the crypt.
Speak with Regis
Your meeting with Regis will reveal that a Resonance potion can help track down Dettlaff. However, the potion requires some extremely rare ingredients such as a Spotted Wight. Regis will tell you where you can find one. Wait until the cutscene is over and then it is time to hunt down a Spotted Wight.
Go to the Trastamara Estate Ruins
Travel west from the cemetery toward a creepy-looking manor on a hilltop. Follow the waypoint on your minimap to lead you straight toward it.
You’ll need to take out the Barghests that you encounter along the way. You’ll also find spoons everywhere in the area. Head toward the doorway to trigger a cutscene. Geralt will read the inscribed curse on the walls.
You will require some spotted wight saliva for the potion. There are two ways to get it, one involves fighting such a creature and the other revolves around alternative methods. We will be going with the latter option since that way we can lift a curse, which is a nice thing to do, and get our required item.
To lift Wight’s curse, you must thoroughly search the area using your Witcher Senses. Items marked in red hue will tell you more about Wight’s Curse and her obsessions.
The items that you find related to the curse include a Soiled Letter, a Stained Diary, a Decaying Letter, and a Book.
A recurring item that you will find here is Spoons so be sure to examine them. Enter the farthest right room and search for a spoon-shaped key. This key is necessary for starting the Spoontaneous Profits! secondary treasure hunt, so remember to pick it up.
Look to your right from where you found the key and head down the staircase. Now take another right to enter the Wight’s Lair, where you will see a table and cauldron in front of you.
Wait till you are prompted to hide inside the cupboard. But before this, you must approach and examine the Wight’s cauldron.
This step is only needed if you want to lift the Wight’s curse. Skipping it will result in you being forced to fight the Wight and drive it away.
How to cure the Wight
Stay inside to spy until Wight notices. You’ll then be prompted to lift Wight’s curse and be given three options: to eat dinner without spoons, with spoons, or by changing the spoons.
To lift the wight’s curse you’ll need to eat without spoons. You will do so after which you will pass out but the Wight runs away. Wake up, take the saliva from the cauldron and follow the stench of the brew to find the wight who has now transformed into an old woman.
You will then take the woman, whose name is Marlene, to Corvo Bianco Vineyard. Talk to her later and you can ask her to stay where she will work in the kitchen. By curing her, you can satisfy one of the conditions required in the quest There Can Be Only One.
You can also scare her where she runs away or if you absolutely feel the need to, can kill her. Doing so will earn you several items which include Greater Triglav runestone, a Green mutagen, a Monster liver and heart, Wight saliva gland, Disgusting Wight Key, Wight Ear, Wight Trophy, Wight Hair, and a fork.
Fighting the Wight is very simple, just be ready to dodge as soon as she launches herself into a few spoons. She can grapple and stun you at this moment so be ready.
However, Geralt has a personal code where he doesn’t fight sentient monsters and spares them. So, if you want to remain in character, curing her seems the better choice.
Go to the Tesham Mutna Ruins
Return to the Mere-Lachaiselongue Cemetery to talk to Regis. To find the remaining ingredient, the game will take you to Tesham Mutna. You have the option to either immediately head there or to wait until you are fully prepared.
As you enter Tesham Mutna, the first room will have a few additional rewards that include pieces of the Tesham Mutna armor. Continue following Regis until you enter a room downstairs, you will find the remaining pieces of the Tesham Mutna armor set and some wall signs.
The final armor piece, the gauntlets, can be found in the hole to your left. Eventually, as you continue to head further along the hall, following Regis, you’ll trigger a cutscene.
You are then handed over the bait for luring the monsters, remove the debris, place the lures and return back to Regis. A fight will now commence where you’ll have to defeat a bunch of necrophages and a Katakan.
Use Quen to fend off exploding Rotfiends and Scurvers. For added damage on Nechrophages use Nechrophage Oil on your swords.
Keep on fighting the monsters and wait for Regis’s Bloodlust to build. It’ll take about 10 kills after which Regis will transform. Grab the last ingredient and return to the cemetery to brew up the mixture.
After a little conversation, a cutscene will be triggered where you are shown Count de la Croix’s death.
