"Zelazny likes to develop different systems of magic, but his emphasis is on systems. He feels the magic should be worked out and contain no contradictions. It should run more like science and not be too supernatural in which anything goes. That route leads to magic being a crutch to move the plot along. He also likes to use the mystery plot. He feels that there is an elegance to having a puzzle overlaid on a fantasy or SF novel. The mystery helps build the mythic elements in fantasy, but is also akin to the process of discovery in science."