This Side Story begins in Stonegard Heights, in the northwestern house. The Bookbinder is trying to read a tome, but it’s in a language he doesn’t understand, as it’s a fairly old language. You will need to revisit Rippletide, with either Primrose or Ophilia in your party, and seek out the Exotic Grandma. She is located on the docks in the southern side of the town, so use Allure/Guide on her, then bring the grandma back to the Bookbinder in Stonegard to finish.