Vilus the Impure, resurrected servant of the lich Tyball, gathered the enemies of the Crux Ansata together at the Nujel'm cemetery. He explained that he had been searching for three special reagents needed to bring Tyball back to the living world, and he'd located the first: a Sprit Dragon's heart.
He revealed that small group of Seers of the Moonstone had made their home in the Serpentine Passage of Ilshenar, and that they had made contact with a spirit dragon who lived in the passage. His plan was to simply attack the Seers headon, and hopefully provoke the spirit dragon into coming to the Seers' defense, so it could be killed and it's heart taken.
He led his assembled army through the streets of Mistas where a Seer was found with his summoned Water Spirits. They were killed and the group moved onward to the Serpentine Passage, where much heavier resistance was met.
Finally, after much fighting and many deaths, White Cloud the Spirit Dragon appeared. and, after a brutal battle, finally perished beneath the onslaught. Vilus cut out White Cloud's heart and went on in search of the next reagent.