Adventure description from the front page:
Traps. Treasures. Unspeakable horrors. All of these and more spring to mind when a story involves the ancient ruins of a wizard's tower. The Kingdom of Sunndi calls on you to explore such a building out in the wilderness, to negotiate your way across the Vast Swamp and the Spine Ridge, and hopefully find the answer to the bullywug invasion laying waste to their lands. A two-round core adventure set in Tilvanot Peninsula for characters level 4 - 15 (APLs 6 - 14).
The final part of "When the Wind Blows" (SND3-01 Harvest Time, ESA4-06 Wind Reaping, and ESA5-02 Seeds). It is not necessary to have played these adventures.