Near the jungles of Chult, beneath the waves of Refuge Bay, lies a ruined city. Evil hags and their minions make their home among the ancient relics. Even deeper down, at the bottom of an old undersea lake, an otherworldly monstrosity guards its eclectic hoard of oddities. What does it know about the Soulmonger? An adventure for characters between levels 4-6 Requires the Tomb of Annihilation adventure This 44 page adventure adds Ishau as a location to your Tomb of Annihilation campaign. It describes the city's history and current inhabitants, including maps, new monsters, and treasure. In an undersea temple, characters face off against a coven of sea hags. The sunken wreck of the Decapus is the lair of sea spawn pirates. And among the ruins lurk giant crabs, skeletal sharks, vegetan mummies, and other monstrosities. A second location, complete with keyed maps, is available to characters who wish to dig deeper: the underwater island-domain of a Morkoth, pulled into Chult by Acererak's magic. The Morkoth's home is in disarray. Trophies it collected from across the multiverse are now running wild and its treasures are being looted by marauders from Ishau. If the characters help, it may share its secrets with them.