From the first page of the PDF:
A radical dissident makes dark alliances and takes drastic measures to advance his political agenda. Is there time to stop the evil he has set in motion? A Living Forgotten Realms adventure set in Urmlaspyr for characters of the Heroic tier (levels 1-10).
This adventure is part of Chapter 1 of the Desolation series. Chapter 1 includes four Heroic tier adventures leading up to the conclusion in CORE5-1. The other three parts are SPEC4-5, CORE4-3, and CORE4-5. You can play these four adventures in any order, but you should try to play them with the same character, and you should try to play all four parts before you play CORE5-1. The Desolation series also includes Paragon tier adventures (starting with SPEC4-6). It is not expected that a player can follow both tracks with the same PC.