What Goes Around Comes Around

I'm a forensic pathologist, performing an autopsy on a body from a fire. The deceased is female, 165 centimeters tall and weighing 48 kilograms. Her limbs aren't curled up, and there are no traces of ash or soot in her mouth, suggesting she died before the fire. There's a ring on the ring finger of her left hand. Remove it and send it to the technical department for identification. "Sister Liu, this looks like a blue diamond. I'd guess it's twenty or thirty carats." My assistant was helping me, head bowed as she examined the diamond ring we'd just removed from the tray. "So what if it's big? It's cracked now, so it's worthless." I gazed at the woman's body, lying still on the stainless-steel autopsy table, and felt a strange pang of sadness. After handling so many unnatural deaths...