A Living City Adventure
From the introduction:
Due to a number of events in the city, including the large amounts of wild magic and the numerous uses of gate spells, the barrier between the Prime Material Plane and the plane of Limbo has been pierced. The effect of this is that a vent of pure, raw chaos is spewing into the Prime Material Plane. This chaos has begun to corrupt and change everything it contacts. The chaos has taken many forms, but the vent appears in the Prime Material Plane as a sparkling waterfall on the Fire River. The chaos is particularly drawn to the purest forms of things and corrupts them. The result is that people no longer behave normally. Even the wild animals have begun to change their nature. Even the Gods have cut off most contact with the Prime Material Plane, fearing the chaos will corrupt them as well. The PCs, due to their prolonged exposure to wild magic, have not yet been affected. They must find a way to close the chaos vent before too much is changed. If they can act in time, the effects of the chaos will wear off.