Gavrel knows the spell is not moveable, so you enter the greathall again. The swords triggered when you got close to the bodies at the bottom of the stairs so you go wide around and then approach from the far side. When you get close enough, he gathers you together and amounted you not to cross the line other than up the stairs.
Casting the spell in the bodies, you move past them, and up the stairs. The spirits do not take up blades this time.
The stairs circle back and lead you to a walkway looking down the greathall on the second floor. There are six doors, two on the left, two on the right, and two on the far wall. These are all likely bedrooms.
But immediately in front of you are more bones. Judging by the jumble of dry bones, a great battle took place here along the upper landing. Ten skeletons clad in moldy fragments of drab grey cloth, one with a cleft skull, another with a severed head, are a chilling testament to the blood spilled in this place.