From the first page of the PDF:
“Shadows long at rest stir, and they hunger for all Faerûn.” Was the oracle Saharel talking about Netheril? Are they responsible for the dark forces now raging in the Dalelands? This is a Special (combat intensive) Living Forgotten Realms adventure set in the Dalelands for characters of the Paragon tier (levels 11-20).
This adventure is chapter two, and the Paragon tier introduction, to the Desolation series. The series has both Heroic and Paragon tier adventures and it is not expected that a player can play both tracks with the same PC.