The Prevention quest in Kingdom Come: Deliverance 2 – Mysteria Ecclesiae DLC is all about helping the monastery’s doctor, Zacharias, create a special plague outfit to protect himself from the spreading illness. In this quest, you’ll gather materials like rope, leather, and herbs, learn how to brew aromatic oil, and finally craft the protective mask and outfit.
Prevention Quest Guide in KCD2

Once you’ve started the Prevention quest, make sure to talk to Zacharias, the doctor, again inside the infirmary. He’ll give you some useful hints about where to find the materials you need. Also, look for the dialogue option marked with a golden quest icon that says “Can I help you with anything?” and go through every conversation choice with him before heading out.
Finding the Flax Rope

The first thing you’ll need is Flax Rope. Head north of the monastery to the church construction area. You’ll find the rope lying on the ground just above the hole there. You’ll notice two workers chatting nearby. To grab the rope safely, throw a rock to lure them away, then quickly snatch the rope once they move.
Getting Leather

Next, you’ll need some Leather. There’s an easy-to-pick chest north of the church, under a white tent by the road. Inside, you’ll find a Cow Skin.
Collecting Mint and Sage

For the herbal ingredients, head to the Woodland Garden located southeast of the infirmary. Go through the small gate to the east of the infirmary entrance to reach it.
- Mint grows at the southern edge of the garden.
- Sage can be found at the northern edge.
You’ll need four of each. While you’re there, also grab 3 Camomile and 1 Valerian from the same planter area, just a bit east of the mint and sage.
Getting the Aromatic Oil Recipe

Now head over to the library inside the monastery. Look for the bookstand in the southwest corner of the room and interact with it. Flip through all the pages of the book to learn the Aromatic Oil recipe.
Brewing the Aromatic Oil
Return to the alchemy bench in the infirmary. Here’s how to brew the oil step by step:
- Add oil from the top left shelf (third jar from the left).
- Add 3 Camomile to the cauldron, and boil for 3 turns (flip the sandglass three times).
- Grind 1 Sage, then add it to the cauldron.
- Boil for 1 more turn, then raise the cauldron.
- Grind 1 Valerian and add it in.
- Finally, take a phial from the bottom left shelf and pour the mixture to get Fragrant Oil.
If everything is done correctly, the recipe will complete successfully.
Making the Plague Outfit
Once the oil is ready, turn around from the alchemy bench and interact with the table in the same room. You’ll see the prompt “Make a plague mask” if you have all the materials.
When you craft it, you’ll hand over the following from your inventory:
- 8 Mint or Sage
- 1 Cow Skin
- 1 Fragrant Oil
- 1 Flax Rope
The screen will fade to black, and you’ll automatically receive the Plague Outfit, unlocking the “Better Safe Than Sorry” achievement or trophy.
That wraps up the Prevention task in Kingdom Come: Deliverance 2 – Mysteria Ecclesiae DLC. Once you’ve completed it, you’re one step closer to curing the plague and saving the monks of Sedletz.
