This guide details how to complete the "For Whom the Bell Tolls" quest in Kingdom Come: Deliverance 2. This main quest follows "Wedding Crashers," and involves saving Hans from execution in Trosky Castle.
1. Hauling Sacks: Begin by transporting sacks from a wagon to a nearby shed. This is a mandatory task.

2. Assisting the Blacksmith: Next, help the blacksmith by crafting a horseshoe using materials found at the forge. Deliver the finished horseshoe to the stables.

3. Aiding Fanka the Cook: Retrieve a lockpick from a red pot in the forge. Use it (or not) to help Fanka, the cook, gaining access to the castle kitchen. Helping her improves your reputation.

4. Interacting with the Chamberlain: Speak with the ailing chamberlain in the kitchen. Persuading him to allow you to brew a Digestive Potion grants access to the surgeon's workshop. Otherwise, stealth is required.

5. Crafting the Fever Tonicum: In the surgeon's workshop (accessed either through persuasion or stealth), create a Fever Tonicum. If you persuaded the chamberlain, you can also craft a Digestive Potion.

6. Treating Thomas: Deliver the Fever Tonicum to Thomas. If you helped the chamberlain, this is straightforward. If sneaking, use stealth to reach Thomas' room, potentially distracting a guard with a pebble.

Successfully treating Thomas before the bell tolls twelve times increases your reputation. However, a successful outcome is guaranteed regardless of timing.