In Volume Three, you’ll return to Castle Frankenstein, which you’ll build as a fully realized 300-piece 3D puzzle (which sits atop the 2D puzzle floorplan from Volume Two). Then you’ll have to solve a set of fiendish puzzles in order to learn how to construct the elaborate origami roofs for the various castle buildings. Finally, you’ll progress through a series of “advent calendar” style diary entries while searching out details in the castle, each time placing a new window into the 3D puzzle. By the time you've finished, you’ll have finally learned Mary's terrible secret...and created a beautiful object you just might want to keep on your mantle forever.