For the Beekeeper's Apprentice, I used the maze pattern to represent the mystery's winding path, the chess queen to symbolize the powerful female villian (and the ever present chess games between Mary and Holmes) and bee honeycomb to tie into the title and Holmes' retirement occupation.
I created the maze in this cover for O Jerusalem using the iconic Dome, the second half of the circle represents the cavern under the city, an eight pointed star ties in with Islamic art patterns, and the circular maze references the labyrinth traditions of several religions. Several layers outside of the highlighted circle, the path outlines a bomb shape referencing the story plot line.
The final cover is for The Moor. I used a plain grid for most of the maze, but added the concentric circles to show the blasts of the gold seeding charges used to try to create a false gold rush. The small gold circles represent the false gold, the tightly twisting maze references the landscape's stones and the story's twisted plot line, and the lack of maze lines at the bottom point to the fatal