Summary:

Robert Cornelius is a master artisan renowned the world over as an expert in the crafting of "GEM", a brand of dolls who are humanoid in size, shape, and movement.
Before he passes away, Cornelius destroys his house and his workshop, only leaving behind, in his grandson Frants' name, a journal, a key, and an elegantly crafted GEM named "Jade".
But as Frants is soon to find out, a skilled craftsman's work is never safe from those who covet it...