Rescuing the seer before she could be sacrificed basically involved a brutal "Victory or Death" tactic which luckily for the group played out nicely. At the end of the 9 hour encounter-after-encounter session every member of the guard was still alive, although everyone came pretty close to final death and was within in single digits of hit points.
The silhouette of a mighty demon appeared as the heroes left the scene. Someday they would face him, but that day has yet to come.
The story continues in Background Story Part IV: The Rise of the Empire
Background Story Part I: The Dark Prophet Chronicles
Background Story Part II: The City Guard