The Dwarfie Run
The Dwarfie Run had been a half-hour's ride east and south of the church....approximately three miles. In daylight, at a hustle, the group could do this in an hour. However, the group must also go to the church first, and is traveling under conditions of poor visibility. It the group wants to stay together, it will be between two and three hours before they reach the Dwarfie Run. Include the time for the exchanges at the mill, and Kregor's spell will be reaching its limit shortly after you arrive.
The Dwarfie Run is located under a treeless hill, which even in the darkness is obviously both ancient and man-made. The creation of earthworks was not an uncommon practice among the Esk, long ago, and they raised mounds over stone passages to bury their kings and chieftians. They also built underground labyrinths for religious purposes.
The Dwarfie Run cuts into the hill from the eastern side. There is a bit of scrub and loose stone on the approach, providing some cover. You can smell the rancid odor of rotting meat coming from the hillside. The entranceway itself is only about four and a half feet tall and perhaps six feet wide, formed of two upright stones and a stone lintel. Another upright stone stands perhaps ten feet in front of this, blocking clear view of the entrance. The creature you saw would be able to fit through the entrance, but it would have to keep its wings folded and, perhaps, crouch down a little. Surely, it could not charge in such a confined area.