Solasta: Crown of the Magister

This achievement occurs in the Dark Castle when you're first sent to look for gems. After dealing with Lizzaria or whatever it's spelled, you'll enter a blue square to go up a floor. At the next blue square save and enter it, the door by it will open and you can proceed inside to find Aksha. You need to pass a dialog check with her to avoid combat, I picked the one about wanting to talk to Mardracht. Assuming you succeed you'll get the achievement when the conversation ends.