About Konrad...

The secret goods the merchants were selling turned out to be contraband Crimson Marrow.
It seems that most goods traded by the merchants of the Gloomy Depths are illicit items that cannot be traded openly. Perhaps it is thanks to their exceptional ability to operate on the edge of legality that their business has continued here for many years without being exposed by the Creed. However, members of the Merchant Guild seem to think that their collaboration with the Cabbage Mission is upsetting this delicate balance. Since the Cabbage Mission is a pseudo-academic organization searching the ruins for the Bapharian Legacy, it stands to reason that they may have obtained something very special and are attempting to move it via the guild's channels.

Perhaps Konrad was unhappy with this collaboration and was looking for a way out, or maybe he realized that the composition of the goods had changed and rushed to offload them. In either case, he betrayed the guild—and Gaston.