People left the dying Earth and found a habitable planet. Thanks to their advanced technology they conquered or subdued local life forms and established themselves as dominant race. The highly advanced technology allowed some of them literally play gods using Hindu mythology as the basis. We all know the power corrupts, so the whole system became very corrupted very fast. Enter a guy who decided to change the way things work. His name is Mahasamatman, or Sam for short - this is how he prefers to call himself. To the simple people he is much better known as Buddha, or Lord of Light:
Roger Zelazny attempted to create a very ambitious project: a science fiction novel basically showing the emergence of Buddhism from Hinduism while preserving the philosophy of the religions. He succeeded. The novel won a Hugo Award for best novel. I saw people call this the legendary science fiction classic - just take a look at the cover of the latest paperback edition. It also earned Zelazny the status of Master of science fiction and showed his practically unrivaled imagination.
This is not an easy read at times. It is not boring, however by any definition of the world. I would not call the novel to be the best introduction to Zelazny's writings, but it is a must read for any person with even the passing interest in science fiction or fantasy. 5 very well-deserved stars is the final rating of the classic book.