Requires completion of Cyrus’ Fourth Chapter and Alfyn’s Fourth Chapter to unlock. This Side Story is a two-parter, with the first one starting in Clearbrook. Speak to Zeph’s little sister, Nina, inside of their house. It appears that Zeph likes someone from his childhood and can’t concentrate on making medicine, as his thoughts are filled with this Mercedes lady. He has written a letter for her, but hasn’t sent it, so take it off of his hands using Purchase or Steal (Letter from Zeph). The only clue you have is that she likes books. Fast travel to Atlasdam and head to the library, where you’ll find Mercedes behind the desk. Deliver the letter to her to finish this first part.