Check out this new article Wizards of the Coast posted recently:

Pearl of the Sea Mother

Insane kuo-toas have located an ancient shrine that was cast into the ocean by their goddess. Within the ruins they located the sacred Pearl of the Sea Mother. Unless these kuo-toas are stopped, they will use the artifactís power to drown one coastal settlement after another in a tide of madness. The player characters must journey into the sacred shrine of the kuo-toa goddess, steal the Pearl, and return it to the surface to destroy it.