A magic item using technology originally created by alien beings called the Mi-go. Can be used to extract information from corpses or plants. If the plates are clamped around a head (or what passes for one) of a mortal being, and the fleshy tube inserted down the throat, the key is wound, and the switch toggled, it can be used to speak with it. Unlike speak with dead, this technology connects to the body, not the soul, turning the body into something whose psychic significance can be read.
First Reference: Chapter 81
Other Notable References: Chapter 83, Chapter 158, Chapter 160