I can't believe this book is so big mostly due to the fact that the pages turn very easily, but also because the story seems simple enough to pass by in fewer pages. Despite that the pages turn easily, I still found myself regularly needing a reading rest, only after short times eagerly picking the book up again to continue it.
There are people who think they are ancient Greeks fighting the Siege of Troy on a terraformed Mars, people of the future using their technology to act out the roles of the Greek gods, people of the near future living controlled lifestyles, prisoners on Earth satellites governing aforesaid people, and bio-machines patrolling the outer planets who notice Solar-system endangering quantum tunnelling activities being used by those creating the illusion of being Greek gods.
It is wonderfully complex and has a brilliant array of characters from an unimaginable variety of local universes. Eventually the existences of all the characters is seen to come from a single history line, but the stories in which the various characters engage only partly merge. It is probably this latter aspect that makes the book so appealing, as plenty is left to the reader's imagination.
In the end the outer-planet protectors reign havoc over the (eventually seen to be nasty) Greek gods, as simultaneously the basic Earthlings have an adventure culminating in the destruction of the planet's imprisoners, and the impact is that both Earth's and Mars' social structure are torn apart and humans must learn to live as humans once again. These two universes are married by the fact that the Earthlings watch the Martians' activities like a soap-opera, and then the entire book is given a massive twist by the appearance of a Greek hero on Earth.
It is wonderfully complex and outrageously imaginative, but you really can't help believing in all the fantastical people you come across in this story. Wonderful.