In the Mysteria Ecclesiae DLC for Kingdom Come Deliverance 2, one of the quests titled “Prevention” involves Henry crafting a Plague Mask to protect him from a plague which is killing all of the inhabitants of a monastery. This guide will help you locate every ingredient, brew the Aromatic Oil, and piece the mask together all while evading guards that have been placed there to enforce quarantine, ensuring Henry’s safe passage through the infected grounds.
Why is the Plague Mask Needed?
In the quest “Prevention,” Henry has to face the worsening plague afflicting the monastery. Even moving around has become difficult as quarantine restrictions are in place and guards are assigned to keep the situation contained. To allow his investigation to continue without further danger, Henry needs to develop a Plague Mask — a protective hood that requires careful gathering of materials and stealth to craft.
You’ll need a handful of specific items to make the mask: Aromatic Oil, Mint, Sage, Flax Rope, and Pig Skin. Most of these must be gathered by hand, and slipping past the guards becomes just as important as finding the ingredients themselves.
How to Locate the Required Items for the Plague Mask
Here’s how you can easily locate everything required for crafting the Plague Mask:
Locating the Aromatic Oil Recipe
The recipe itself can be found in the monastery library. Look for a lectern in the southwest corner — reading the book placed there will automatically add the Essential (Aromatic) Oil recipe to your inventory.
You can choose to talk to Crispin, the librarian, but doing so means explaining why you’re violating quarantine. It’s easier to slip in quietly and read the book without a word.
Gathering the Herbs
Your journey begins in the Woodland Garden, found southeast of the monastery near Herbalist Joachim’s hut. Since Joachim isn’t available for trade, the herbs will have to be picked directly from his garden. Collect the following while you’re there: 1 Sage, 8 Mint, 3 Chamomile, and 1 Valerian
Although the quest objectives only highlight mint, you’ll later use chamomile, sage, and valerian to create Aromatic Oil, so it’s worth collecting everything now.
Securing Rope and Pig Skin
Once you’ve got the recipe, it’s time to find the materials for the mask’s frame. The building site located south of the chapel, on the western edge of the monastery grounds, has what you need — Flax Rope and Pig Skin.
The Pig Skin lies on a table on the north side of the site, while the Flax Rope can be spotted on the ground near a barrel beside a cart. Keep an eye out for patrolling guards — being caught outside the infirmary will get you sent straight back.
Brewing the Essential Oil
With all your herbs in hand, you can now brew the Essential Oil. The alchemy bench inside the infirmary’s back room is the easiest to access, though another one sits near Joachim’s hut if you prefer working there.
To brew the Essential Oil, start by adding Chamomile to the cauldron and let it boil for three turns. Once that’s done, grind the Sage and stir it into the mixture before allowing it to boil for one additional turn. Afterward, grind the Valerian and add it to the cauldron as the final ingredient. When everything has blended properly, pour out the finished oil, and with that, your Essential Oil will be ready.
Crafting the Plague Mask
Return to the infirmary’s back room, where you’ll find a worktable near the alchemy station. This is where you’ll assemble the Plague Mask. With all your ingredients gathered — Aromatic Oil, Pig Skin, Flax Rope, and herbs — interact with the table to craft it.
When the mask is complete, the “Prevention” quest concludes with Henry now being able to explore the Sedletz crypt and uncover the truth behind the plague’s mysterious origins without putting himself at further risk.
