Welcome to Ilium. Post-humanity has evolved into something very far removed from human. They have recreated themselves as the Ancient Greek Gods and have recreated the Trojan War. This story is then told through the eyes of several individuals. There is Dr. Hockenberry, who is a classical scholar from the 20th Century, resurrected by the gods to keep a record of the events of the Trojan War and to compare it to the Illiad. He is subverted by one of the gods to assassinate another god and this sets into motion a chain of events that will have severe consequences.
There is also a group of "old-style" humans in Daemon (I did not like this guy at all), Harman (the last man on Earth that can actually read), Ada, and some others who must find an ancient myth in the Wandering Jew to figure out just what happened to the Earth and to humanity. What they fid will shock them and change their view of everything.
Finally, there are the robot moravecs Manmhut and Orphu. These two were very cool characters and as they try to unravel what is going on with the posthumans and their plans for Mars, their interesting banter about Shakespeare and Proust was rather interesting.
I know that sounds confusing, but I didn't want to spoil this crazy story. It was a very entertaining and novel concept. Dan Simmon's writing style is always exciting, but it is obvious that his depth of interest is wide and varied.
An interesting take on the Trojan War and I thought the idea of a historian who is able to go to see great battles to compare them to the written histories to be a wonderful concept. Where does one sign up for this?