human
Produce a detailed written description of a eerie scene inside a building keep with flames, granite, ore, floor, and keystone.
assistant
Enormous granite blocks, fitted with no visible mortar, create thirty-foot walls and a vaulted ceiling. Thick veins of ore meet in a whorl in the center of the floor. In the east wall, a wrought iron keystone twenty-five feet above the floor supports a red granite arch which is flanked by two fifteen-foot-high granite arches, one black and the other grey. Flames that light the chamber rise from a trough along the top of each wall.