From Introduction: The Ma-Gog Delta is the coastal area where the two greatest rivers of the Shattered Empire meet. It is swampy and full of bizarre creatures and river pirates (see the Gaz4: The Floating Cities Gazetteer for details). The only reason to come here is the fabled Library of Collected Water Knowledge, either to research a special water spell or to take the legendary Blue Scroll, a magic item that is not that powerful by itself but it is nevertheless part of several important mythical stories.