From the back of the book:
The Savage Tide Rises!
The first Savage Tide has already touched the mortal world, yet none who live today recall this terrible time of red ruin. It swept over an ancient city, transforming beggar and noble, merchant and thief, resident and visitor, one and all into feral, ravenous fiends. What took the ancients hundreds of years to build came crumbling down in a matter of days. When the tide’s final ripples faded, only ruins remained.
Now, after a thousand years, the hidden architect of the Savage Tide gazes upon new targets. This time, the doom will not be limited to one hapless city. This time, all of civilization is perched on the shore, blissfully ignorant of what the tide is about to bring in.
The Savage Tide Adventure Path is a complete campaign featured over the course of a year in DUNGEON magazine. Running from issue #139 to issue #150, the campaign takes your PCs from their lowly beginnings at 1st level to the lofty heights of 20th, and possibly beyond. It all begins in the exotic port city of Sasserine, detailed in this booklet. The Savage Tide begins here! Will your characters stand upon its shore and protect the civilized world? Or will they succumb to its rising waters of ruinous rage?