In Kingdom Come: Deliverance 2, Lord Semine and Agnes's wedding faces a snag: the groom's gift, a sword, is missing. Your mission: recover it.
Finding the Sword Thief
Radovan reveals the sword's disappearance, mentioning a suspicious individual in yellow clothing. Investigate those wearing yellow. While most deny involvement, one points towards the stable's upper level. There, you'll find Hans, romantically involved, but innocent of the theft. However, Hans witnessed Svatya, the bailiff's son (and the bride's brother), taking the sword. Hans, unable to track Svatya, leaves the investigation to you.
Locating and Questioning Svatya
Find Svatya near the musicians by the stables; he's easily identifiable by the sword in his possession. He confesses to the theft, motivated by resentment towards Old Semine. His plan was to embarrass Old Semine by making it seem like he'd misplaced his son's gift. Svatya reveals he tossed the sword into a nearby pond.
Retrieving the Sword
Locate the pond (easily found behind Radovan or via a path from a dance with Myshka). The sword is visible in the water; retrieve it.
Returning the Sword and Conclusion
Return the sword to Radovan. You can either reveal Svatya's guilt or downplay the incident. Once the sword is returned (and any time-sensitive tasks completed), the wedding commences. Congratulate the couple and proceed with the main quest.