Interrupted Observance

From DeadGoblins

The group went its separate ways after The Mourning. After another two years, The Treaty of Thronehold was signed and The Last War was ended.

Four years after The Mourning, each of the group received an invitation from Bren ir'Gadden, asking them to attend a remembrance ceremony in Sharn on Olarune 20, 998 YK, the fourth anniversary of the Day of Mourning. Soon, the group was catching up with each other amongst some nobles and military leaders on a rooftop, although ir'Gadden had not yet shown up. Suddenly, a demon surrounded in the dead-gray mist that borders the Mournland appeared on the rooftop. It was a Mourning Haunt. The Haunt immediately went after some nobles, killing four of them. Lan tried to rescue a few before they died, but was unable to. As the rest of the bystanders fled, Lan, Sentinel, Khav and Kurvilis corralled it around the roof. The demon was almost impossible to hit, and after awhile it was obvious it came for the four of them. As the fight went back and forth across the rooftop, the demon became hurt and stopped producing mist, making him easier to hit, but not much easier to kill. Eventually, after a long and difficult battle, Khav was able to drop the Haunt, and as it died it displayed the Mark of Prophecy the group had seen exactly four years before.

This lead to a couple of questions...where did it come from and who sent it?