C707

Not far away, in an inconspicuous corner, there was an oval shaped stone inlaid into the stone wall. The rock was not big, only the size of a palm. The top of the rock was abnormally sharp, like a sharp sword. When the light shone on it, it emitted a cold light. The color of the stone was also black. It was exactly the same as the surrounding stone walls. If one didn't look carefully