In the Witcher 3 quest, "Ashen Marriage," Geralt assists Triss Merigold and her fiancé, Castello, in their preparations for a swift wedding in Novigrad. His tasks include ridding the canals of monsters, procuring alcohol, and selecting a wedding gift for Triss. The gift's significance impacts Triss's response; a memory rose, a callback to Witcher 2, evokes a powerful emotional reaction, unlike more mundane presents.
However, Dijkstra's revelation of Castello's connection to witch hunters throws a wrench into the proceedings. Castello is revealed to be under duress, blackmailed by the hunters who threaten to expose his daughter from a previous marriage.
Geralt has the option of revealing this truth to Triss, either privately or with Castello present. Regardless, the wedding is called off. Triss's reaction varies depending on the method of revelation, ranging from disappointment to gratitude for Castello's honesty, but ultimately, she concludes the marriage was premature.
This plot point presents an opportunity to deepen Geralt and Triss's relationship and further develop supporting characters.