When the Vestige first meets Amuur, he is assisting the local alchemist, Hendil, dealing with the mysterious plague that is affecting the village. He helps with making the salloweed aloe that helps to keep the disease at bay.
As the Vestige looks into the source of the disease, it is discovered that Hendil's son had been attacked and turned into a vampire and that his feeding on the people of Phaer was the real reason behind the disease. The salloweed aloe that he and Hendil were using was actually meant to weaken and make people easier to feed to him.
Amuur had full knowledge of what was really going on, and when one confronts him and Hendil at the bottom of the town mine, Amuur fights and is killed by the Vestige attempting to keep the secret.