In *Kingdom Come: Deliverance 2*, the "Canker" side quest is an early opportunity to score a mace or some extra Groschen, and you'll need to have completed "The Jaunt" beforehand. Here's how you can successfully navigate the "Canker" quest:

Pick Up the Canker Side Quest

To initiate "Canker," you need to have a chat with Gules at Semine. It's particularly convenient to pick up this quest during the wedding of Lord Semine and Agnes, as you can talk to Gules while he's enjoying a drink. Alternatively, if you visit Semine earlier, you can find Gules on patrol and strike up a conversation. Ask him about his past with a band of bandits and offer your assistance in clearing them out. Canker is one of these former bandits and your first target.

Find and Kill Canker

Once you've accepted the quest, Canker's location will be marked on your map, north of Nebakov Mill. Be cautious as the path to this location is often patrolled by bandits who might ambush you. You can choose to sneak past them, engage in combat, or simply make a run for it. While these random bandits aren't particularly challenging, it's best not to arrive at your destination already wounded.

The bandit camp where Canker resides is nestled in the mountains, and it's easy to overlook because you must navigate through a narrow gap to reach it, similar to accessing the Hermit's house during the "Wedding Crashers" quest. Make sure you're prepared for combat before entering, as you'll encounter several bandits along with Canker.

The order in which you take down the bandits can cause some to flee. However, you'll need to defeat most of them, so don't let your guard down. Fortunately, Canker will stand his ground, ensuring you can complete the quest by killing him.

Finish the Quest and Return to Gules

After dealing with Canker and his crew, loot his body to collect the Light Mace, which serves as proof of your deed. Feel free to take any other items you find useful. Then, make your way back to Gules to wrap up the "Canker" quest.

After completing "Canker" in *Kingdom Come: Deliverance 2*, you'll need to wait a full in-game day before you can continue with Gules' storyline. Once the day has passed, speak with Gules again to start the next quest, "Handsome Charlie."