From the publisher's website:
A Pathfinder Society Scenario designed for 1st level characters.
Dispatched on an envoy mission overland from Absalom to port city Escadar, you must weather the harsh wilderness of the Isle of Kortos before you can hope to meet with the representative of the elusive gillmen, and only then come face to face with the greatest threat to the Pathfinder Society.
This scenario is designed for play in Pathfinder Society Organized Play, but can easily be adapted for use with any world. This scenario is compliant with the Open Game License (OGL) and is suitable for use with the Pathfinder Roleplaying Game.
A Vision of Betrayal is the final part of the three-part First Steps campaign arc, designed specifically for 1st level characters as an introduction into the Pathfinder Society Organized Play. It is the sequel to Pathfinder Society Scenario Intro 1: First Steps-Part I: In Service to Lore and Pathfinder Society Scenario Intro 3: First Steps-Part II: To Delve the Dungeon Deep. Starting July 28th, these scenarios will be available as a free download from the publisher.