Shiny, sparkly... deadly?

The gems from a necklace owned long ago by a notorious woman are killing people in the here and now. But where has the necklace been for the last several hundred years? Why has it surfaced now? And most importantly, who would disassemble such a gorgeous work of art? Mallory certainly wants to know. But it's not until yet another corpse surfaces that her sleuthing team hops on board to help.