Pathfinder Adventure Path: The Apocalypse Prophet (Extinction Curse 6 of 6) - Rules of Play says:

“The Apocalypse Prophet” is a Pathfinder adventure written by Lyz Liddell for four 18th-level characters. This adventure concludes the Extinction Curse Adventure Path, a six-part, monthly campaign in which the heroes lead a traveling circus as they unravel a plot to eradicate all life from the islands of the Inner Sea. This volume also includes a gazetteer of the forbidding Kortos Mountains, an examination of relics left by the dead god Aroden, new monsters, and new rules.