If you already completed vagabond's camp, the only thing left to do is a mini-quest for the village alchemist in the first village close to the castle and reforging the puzzle sword from 3 pieces.
If the alchemist is selling lust drafts, this means you already did this quest.
If not, check out the cave with skeletons, it's in the Northern part of the desert. In the last room there, you'll find a letter envelope - try picking it up and Ada will find the quest item for the alchemist.
