In Kingdom Come: Deliverance 2, Hans's main quest, "For Whom the Bell Tolls," requires crafting a Fever Tonic to save someone at Trosky Castle. This guide details how to acquire the recipe and brew the tonic.

Obtaining the Fever Tonic Recipe:

There are two methods to access the Surgeon's Workshop in Trosky Castle, where the recipe resides:

• Stealth: Sneak into the workshop.
• Diplomacy: After delivering the horseshoe in "For Whom the Bell Tolls," speak with Cook Fanka. Offer to help her with her locked chest; she'll lead you to the noble's kitchen. Convince the ailing Chamberlain you can improve his health (skill checks involved). Success grants workshop access. Crafting a Digestive Potion alongside the Fever Tonic further strengthens your case and allows you to meet Thomas.

If diplomacy fails, steal food, exit the kitchen, and use another set of stairs to access a different kitchen. Bribe the guard with the stolen food. Then, sneak upstairs to the Surgeon's Workshop. The journal containing the recipe is on a bookshelf.

Brewing the Fever Tonic:

The necessary herbs are already on the surgeon's station. Follow these steps:

1. Pour wine into the cauldron.
2. Add 3 handfuls of Feverfew.
3. Lower the heat and boil for 2 turns of the sandglass.
4. Grind a handful of Elderberry Leaves.
5. Add the ground Elderberry Leaves.
6. Add 2 handfuls of Ginger.
7. Take a phial from the bottom-left shelf.
8. Distill the tonic using the Still.

More herbs are available in the chest if needed.

Completing the Quest:

After brewing the Fever Tonic, deliver it (and the Digestive Potion, if crafted) to the Chamberlain to meet Thomas. If you didn't gain the Chamberlain's trust, use the noble's kitchen to sneak to the chapel and find Thomas and Adele. Speak with Adele to conclude the quest.