The Mines of Madness
The former mine forman
The magical that suffuses the mines, had an unintended side effect: They released arcane energies that drove the original dwarves inhabitants past the brink of madness so that they ultimately turned on one another.
Pax Jaggershield, the foreman, was convinced that the others were plotting to seize the mine and its secret for themselves, so he took care of business. After the murder and mayhem subsided, guilt and paranoia kept him from leaving the mines. He started eating rocks (thinking they were cockatrice eggs) and died a painful and ignoble death.